CYTEC.COM
VOLUME 18
CYTEC SOLUTIONS for Alumina Alumina Processing, Processing, Metal Extrac Extraction tion Products and Mineral Processing
CYTEC ALUMINA PROCESSING
Letter from the Vice President Dear Valued Customers, For the past 100 years, Cytec has been a committed partner to our customers and a major contributor to chemical advancements in the mining industry. Our drive has always been to understand the industry challenges and the specific needs of our customers. We continue working to ensure your success by providing products, technical service, and specific solutions based on your key challenges. We have learned a great deal throughout this century and are bringing this knowledge into new and exciting developments that are currently cu rrently underway. Included in this latest edition, you will learn about a few of these innovations in Alumina Processing, Solvent Extraction, and Mineral Processing. The Alumina processing industry continues to face challenges in difficult to settle red mud substrates in the Bayer Process. We have developed the CYFLOC ® Si-7000 series of flocculants which has a new chemistry designed specifically to handle this industry issue. Our new ACORGA® CB1000 Clay Binder is a process aid that optimizes the clay treatment process of the organic phase in the solvent extraction circuits. This is a very simple-to-use, yet groundbreaking product, which promotes organic quality and allows plants to achieve higher flow rates and save costs through reduced bleed requirements and lower entrainment losses. Finally highlighted in this edition are a range of polymer depressants which are a safer and more efficient alternative to NaSH in copper/molybdenum separation. In addition, we highlight our AEROPHINE ® 3418A Promoter that is developed for use on copper sulphides and activated zinc minerals and designed for the efficient recovery of precious metal and base metal sulfide values from ores. Along with our product innovation development, we continue major investments in our sites to assist customers with multiple source points and logistic efficiency. Our newly expanded Phosphine Specialties plant in Niagara Falls, Canada and Canada and the recent opening of our Nagpur, India facility support our customer’s supply needs. needs. Also, we have secured legal entities in countries with growth potential for our customers including Indonesia, Peru, and Saudi Arabia. While we are proud of our accomplishments over the past 100 years, we recognize that it is direct result of allowing us to partner with you and we thank you for working with us. Along with my dedicated team, I look forward to collaborating with you in the future to address the key challenges facing the mining industry and prioritizing the success of your operation. Thank you for your interest and business.
Michael Radossich President, Specialty Chemicals Vice President, In Process Separation 2
CYTEC INDUSTRIES | SOLUTIONS VOLUME 18
Table of Contents: Alumina Processing New Red Mud Flocculants for High Silica Bauxites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Metal Extraction Products Clay Treatment Improvements Using ACORGA ® CB1000 as Clay Binder . . . . . . . . . . . . . 9
Mineral Processing High Performance Synthetic Copper Depressant Delivering Significant Changes and Benefits to Cu-Mo Separation Process. . . . . . . . . . . . . . . . . . . . 15 Application of AEROPHINE ® 3418A Promoter at a Cu/Au Flotation Plant in Asia. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
100 Year Anniversary Timeline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Employee Testimonials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
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CYTEC ALUMINA PROCESSING
New Red Mud Flocculants for High Silica Bauxites D. J. Stigers1* , H. L. T Chen1 , R. Vinhas1 , M. Viggiano1 , C. Rivera1 , R. Bagwe1 , D. Hu 2 , A. Song1 , M. Taylor 1. 1
Cytec Industries, Inc., Stamford, Connecticut, United States Cytec Industries co., Ltd. Shanghai China, Corresponding author:
[email protected]
2
The production of alumina from bauxite requires efficient separation of red mud residue in gravity thickeners to generate pregnant liquor with low solid content. As the quality of bauxite reserves continues to decrease due to increasing levels of reactive silica, more efficient flocculants are needed to prevent these solid-liquid separations from becoming production bottlenecks and increasing costs for alumina producers. Of particular concern is the decreasing performance of flocculants when high levels of desilication product (DSP) are produced in the Bayer process, which have been determined to be bound directly to the surface of Bauxite residue solids. Our new CYFLOC® Si-7000 series of red mud flocculants, have shown a unique ability to settle bauxite residues containing well over 5 wt% silica with excellent settling rates and impressive overflow clarities from field testing. The results will be presented to demonstrate the ability of this new polymer to handle the increasing silica content in the bauxite while maintaining, or even improving, the current flocculation benefits to Alumina refineries.
Introduction
Experimental
The use of synthetic polymeric flocculants for the removal of red mud solids from Bayer process streams is essentially ubiquitous (Rothenberg et a.l 1989; Ryles and Avonits 1996). Developments in the synthesis and application of these reagents have revolutionized the industry by improving settler efficiency and control. At the forefront of these reagents, our CYFLOC® Si-series has seen wide spread use as they are designed specifically to interact with the iron-containing minerals within the red mud solids, providing Alumina producers with a range of benefits (Ryles and Avonits 1996). As Bauxite quality has begun to decrease, due to the higher amounts of silica levels found within the ore, increased levels of formed DSP (desilication product) have the potential to disrupt the surface of red mud solids, thereby impacting the flocculant / mud surface interaction (Dai et al. 2010; Davis et al. 2010a). A recent literature report indicated that DSP formed in the presence of hematite particles can have a negative impact on the performance of polyacrylate (PAA) to settle the solids (Senaputra et al. 2013). The ramifications of this finding would lead the industry to slowly lose performance benefits of these flocculants, thereby increasing costs. W e have responded to these needs by developing the CYFLOC Si-7000 series of flocclulants that are designed to handle red mud containing > 5% silica.
Scanning Electron Microscopy was performed using a Zeiss Sigma VP equipped with a Bruker EDX detector. X-Ray Fluorescence was performed using a Rigaku Primus II X-Ray Fluorescence spectrometer and results were reported as the oxide using the SQ X calculation. X-Ray diffraction measurements were collected on a Rigaku Multiflex diffractometer with a monochromated high intensity Cu-K α radiation operated at 40 kV, 20 mA. Diffraction patterns were scanned at a rate of 2⁰/min over 2θ region from 4-90⁰. Phase identification is done by comparing with a database of known materials published by the International Center for Diffraction Data. Synthetic DSP was prepared by adding 300 g kaolinite to 1.5 L solution containing 80 g/L NaOH, 20 g/L Na 2CO3 and 20 g/L Na2SO4 and heating to 150°C for 30 min in a Parr reactor. The solid material was collected by vacuum filtration.
4
Settling tests were conducted in graduated cylinders using the standard dual addition of flocculant. The initial dose of flocculant (50% of total dose) was followed by 10 moderate mixing strokes of a perforated disc plunger, while the second dose of flocculant was followed by 5 slow mixing strokes. Settling rates were calculated by timing the decent of the mud interface. Once settling was complete, the cylinders were placed in a 95°C water bath for a fixed time, after which the supernatant clarity was measured with a turbidimeter.
CYTEC INDUSTRIES | SOLUTIONS VOLUME 18
Results and Discussions Surface Analysis of Red Mud Solids Digester blow-off solids were isolated from an Alumina refinery before the addition of flocculant, washed with water to remove the liquor and analysed by SEM (Figure 1). Although qualitative, the surfaces of these solids show a remarkable coverage of sodalite and some exposed iron oxide. These mud solids were then treated with HX-2000 in order to be removed from the process. The overflow (unflocculated) solids from this settler were collected by centrifugation, the underflow solids were collected by filtration and the surfaces of both were analysed by Confocal Raman Microscopy (Figure 2). Although sodalite was found to be Raman inactive, the presence of quartz was detected on the surface of the overflow solids. The underflow solid surfaces were primarily hematite and anatase.
solids from select tests were analysed by X-ray diffraction. The performance data in Figure 3 displays the expected overflow clarity trend (as measured by turbidity) on a particular Bayer process residue as the dose was raised. While the total silica content in the original mud was measured at 4%, silica levels of 37% and 63% were found in the overflow solids when 635 g/T and 1650 g/T of flocculant were used, respectively. These results indicate that as the dose of HX-3000 increased, the flocculant continued to reduce the quantity of solids in the overflow, however, it poorly flocculated solids containing silica. This is consistent with the microRaman surface analysis described in the previous section.
Figure 1. SEM images of digester blow-off solids indicating exposed sodalite and iron surfaces
Composition of Unfl occulated Solids Laboratory testing of HX-PAMs can lead to understanding the limitations in solids capture. HX-3000 was used to flocculate red mud solids over a large dosage range and the overflow
Figure 2. Raman mapping of underflow solids (top) and overflow solids (bottom) from a thickener using CYFLOC® HX-2000
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CYTEC ALUMINA PROCESSING
Figure 3. Turbidity versus dose plot for HX-3000 flocculation
of red mud. The silica composition of the initial mud and overflow solids at 635 and 1650 g/T are shown, as measured by XRD Flocculation of Red Mud with Added DSP
As the global leader in red mud flocculant technology, we recognize the need to develop reagents that can remove high silica-containing particles from Bayer process streams due to the increased use of poor quality Bauxite. In order to meet this need, we have developed the Si-7000 series of flocc ulants, which utilizes a new chemistry, relative to our current CYFLOC® product line, which can specifically flocculate red mud containing more than 5% SiO 2 and very low levels of iron. Our initial lab testing was conducted by adding DSP solids to red mud slurry in order to simulate the effect that high silica levels in the substrate have on flocculant performance, a procedure previously reported in the literature (Davis et al. 2010b), that can be used with most globally produced muds. Our new HX-7300 flocculant was performance tested alongside HX3000 with 20% DSP solids added to the mud as shown in Figure 4. Interestingly, both the overflow clarity and settling rate versus dose curves were remarkably similar for HX-3000 and Si-7300, even though the flocculants have different chemistries. Recent literature reports (Senaputra et al. 2013) have indicated dramatic differences in flocculation performance on substrates that are physical blends of hematite and DSP particles, compared to substrates of that contain hematite with DSP bound to the surface. This suggests that the physical blend of red mud and DSP solids could give misleading performance data and only testing with plant generated substrates would yield reliable performance characteristics.
6
Figure 4. Overflow clarity (above) and settling rate (below)
versus dose comparing HX-3000 with Si-7300, using slurry with 20 wt% added DSP solids. Analysis of High Silica Red Mud
Certain Bauxite residues, specifically from China, contain very high levels of aluminosilicates due to the high, reactive silica in the Bauxite itself. As the bauxite is processed, the generation of DSP particles compromises a significant portion of the mud solid, and has a negative impact on flocculant performance (Peiwang et al. 1994). XRF data of these solids are shown in Table 1 and indicate a substantial portion of SiO 2 and CaO, with a minimal amount of Fe 2O3. XRD analysis indicates approximately 55% cancrinite and only 10% hematite. Although these are measurements of the bulk composition, they still give significant insight into the nature of the mud particles. While most red muds produced in Western refineries tend to have higher iron content (> 40%), this particular sample contains very little and as such, is not a good candidate for iron-binding flocculants, like HX-3000.
CYTEC INDUSTRIES | SOLUTIONS VOLUME 18
Table 1. Compositional data of a high silica red mud as measured by XRF COMPONENT �MASS %�
Na2O
MgO
Al2O3
SiO2
P2O5
13.32
0.59
18.86
15.29
0.32
ZrO2
K2O
CaO
TiO2
Fe2O3
0.42
2.12
16.43
10.90
12.64
It is well known that the surface minerology of the solids plays a critical role with respect to flocculant performance. SEM images of these solids show an abundance of aluminsilicates on the surface (Figure 5). Survey EDX measurements (Table 2) indicate a significant amount of Ca, Al and Si on the surface, with a minimal amount of Fe.
6. HX-3000 and HX-7300 gave similar clarities as a function of dose; however, both are dramatically better than PAA. It is worthwhile to note that plants typically do not increase their PAA dosage above 200 g/T due to the negative impact on filtration. Although clarity improves with dose for PAA in these tests, these dosages are well above the 200 g/T limit. The settling rate of PAA increases dramatically with dose as well, but is subject to the same limitation. While it is known that HX-3000 displays significantly less negative downstream effects owing to much more rapid adsorption kinetics than PAA and thus can allow for higher dosing, the poor settling rate performance of this flocculant makes it unattractive for such low iron-containing substrates. HX-7300, on the other hand, displays a positive dose response with respect to settling rate, and will likely not be dose limited like PAA. When these performance metrics are compared with those described in Section 3.3, it is clear that physical blends of DSP and mud cannot be used as testing substrates for Si-7300 and that mud digested from high silica Bauxite must be used to give representative results.
Figure 5. SEM images of digester blow off solids from China with a large amount of surface-bound aluminosilicates
Table 2. Surface compositional data of a high silica red mud as measured by EDX survey analysis MASS % �NORMALIZED TO EXCLUDE O AND C�
Ca
Al
Fe
Si
20.3
26.1
5.8
14.5
Na
Ti
K
Mg
23.2
5.8
2.9
1.5
Flocculation of High Silica Red Mud Laboratory flocculation tests were conducted using this high silica red mud at Alumina refineries which process poorer quality Bauxite. The performance of our Si-7300 is compared against HX-3000 and polyacrylate (PAA) shown below in Figure
Figure 6. Turbidity (above) and settling rate (below) versus dose for PAA, HX-3000 and Si-7300 with high silica red mud. The dashed line represents practical dosing limit for PAA with respect to filtration efficiency. Using this improved performance as an initial step, we have made further modifications to develop the Si-7350 7
CYTEC ALUMINA PROCESSING
flocculant. Performance data for this new product is shown in Figure 7 compared against PAA and the co-dosing of PAA with HX-3000. The turbidity versus dose plot illustrates the improvement that can be achieved in clarity for either codosing of HX-3000 with PAA or the use of Si-7350, relative to PAA on its own. However, HX-7350 has been shown to give an improved settling rate, relative to both PAA and co-dosing with HX-3000. This improved performance is directly related to the new chemistry of the Si-7000 series of products. Significant benefits, such as improved settler throughput and increasing filtration cycle time, can be realized by Alumina refineries processing this lower quality Bauxite by using Si-7350 in place of PAA.
new Si-7000 series of flocculants which have a new chemistry designed specifically to handle these difficult to settle red mud substrates. Although physical blends of DSP and red mud were found to be convenient, yet inadequate for performance testing, the benefits of the new chemistry can be realized from tests using plant produced substrates. These muds contain very little surface exposed iron, as measured by EDX, and a large surface coverage by aluminosilicates. Si-7300 was found to provide excellent clarity and improved settling rates over HX-3000 using this substrate. Si-7350, on the other hand, has shown the ability to give excellent clarity, but also superior settling rates, even higher than PAA. The unique chemistry of the Si-7000 series of products has been tailor-made to interact with the bound aluminosilicate minerals on the surface of blow-off solids to optimize flocculation efficiency. Click for more information regarding our Alumina Processing Chemicals.
References Dai, Q., Davis, M.J., Zhang, R., 2010. New Flocculants for Improved Processing of High Silica Bauxites Travaux, 25, 200204. Davis, M. J., Lewellyn, M., Dai, Q., Chen, H.-L. T., Taylor, M., 2010a. Use of Silicon-containing Polymers for Improved Flocculation of Solids in Processes for the Production of Alumina from Bauxite. US Patent Pub No.: US 2010/0098607 A1. Davis, M., Dai, Q., Chen, H. –L. T., Taylor, M., 2010b. New polymers for improved flocculation of high DSP-containing muds. Light Metals, 57-61.
Figure 7. Turbidity (above) and settling rate (below) versus dose
for PAA, co-dosing with HX-3000 and Si-7350 with high silica red mud. The dashed line represents practical dosing limit for PAA with respect to filtration efficiency.
Conclusion SEM/EDX measurements confirm the presence of aluminosilicates on the surface of red mud solids post digestion, which have been reported to negatively af fect flocculation. Laboratory testing with HX-3000 has indicated a poor ability to flocculate silicon-containing minerals. In order to improve on this performance, we have developed a
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Rothenberg, A.S., Spitzer, D.P. M.E. Lewellyn, M.E., Heitner, H.I., 1989. New reagents for alumina processing. Light Metals, 9196. Ryles, R.G., Avotins, P.V., 1996. SUPERFLOC HX, a new technology for the alumina industry. 4th International Alumina Quality Workshop, Darwin, Northern Territory, 206-216. Peiwang, L, Zhijian, L., Yucai, L., Hailong, C., Fengling, W., Hong, 1994. The influence of the predisilication temperature of bauxite slurry on the sedimentation of red mud and the utilization of which in alumina production. Light Metals, 133136. Senaputra, A., Fawell, P., Jones, F., Smith, P. 2013. Sodalite solids formation at the surface of iron oxide and its impact on flocculation. Light Metals, 77-82.
CYTEC INDUSTRIES | SOLUTIONS VOLUME 18
Clay Treatment Improvements Using ACORGA® CB1000 as Clay Binder Laurent Cohen, Brent Hutzler, Matthew Soderstrom Laurent.Cohen@ cytec.com Brent.Hutzler@ cytec.com Matthew.Soderstrom@ cytec.com Previously featured in Cytec Solutions (vol 17) for its application in crud treatment, our ACORGA® CB1000 also presents value when used as a process aid in the Clay Treatment process. Used commercially in several operations, CB1000 facilitates higher clay dosages while improving the clarity of the final clay-treated organic without any change to the filtration equipment. The ability to treat at higher clay dosages allows improvements in interfacial tension, phase separation time, and selectivity to be realized more quickly while reducing the likelihood of phase instability due to solids being returned to the plant. The improved organic quality will allow SX plants to achieve higher throughput rates, reduce bleed and lower entrainments (aqueous and organic).
Introduction
Current Clay Treatment Practices and Issues
In copper solvent extraction (SX) managing the quality of the organic phase is key to ensuring optimal physical and metallurgical performance in the plant. Clay treatment helps maintain organic quality but achieving the right dosage of clay using existing equipment is often a challenge, the bottleneck presenting itself in the filtration process. To alleviate this problem, we have developed ACORGA CB1000 Clay Binder, a process aid that increases the efficiency of filtration equipment and enables higher dosages of clay through existing filtration equipment. This article discusses common industry practices and related issues in organic clay treatment. It also presents the benefits achieved in commercial operations through the use of ACORGA CB1000 Clay Binder.
To maintain or restore organic quality, current practices consist of treating circuit and/or recovered organic with acidactivated clay, followed by a filtration step. Most operations today use Phase Disengagement Time (PDT) as an indicator of the effectiveness of the clay treatment process. This is often misleading due to the presence of solids in the organic phase. Fine particles are known to accelerate PDT, but the improvement is short lived as solids eventually wash out of the organic. A secondary view of the organic quality is recommended by determining the improvement in Interfacial Tension (IFT), measured by ∆IFT: the difference between the IFT of the clay-treated organic (at x% mass fraction of clay) and that of the non-treated recovered organic:
Importance of Organic Q uality Recent improvements in mixer-settler technologies and new developments in organic recovery processes and equipment allow plants today to recover up to 90% of the total organic leaving the circuit1,2. At the same time, decreasing ore grades have prompted SX operations to increase flow rates in order to sustain production3. This results in intensified utilization of an organic inventory which is renewed less frequently. Over time the inventory accumulates contaminants from the Pregnant Leach Solution (PLS), electrolyte, or recovered organic. Interfacially active, these contaminants negatively impact the physical and metallurgical performance of the circuit, resulting in longer phase disengagement times (PDT), higher dispersion band depths, entrainments, lower stage efficiencies and Cu:Fe selectivity.
∆IFT(x%) = IFT(x%) – IFT(0%) Plants that use PDT as the only indicator of effectiveness fail to realize they undertreat their organic. Suboptimal clay treatment produces little benefit and is occasionally detrimental. Among the most common issues related to clay treatment and their consequences are: • Insufficient clay utilization plants do not use sufficient quantities of clay to remove interfacially active impurities • Clay deactivation insufficient removal of aqueous from the organic results in clay deactivation and inefficient impurity removal
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CYTEC METAL EXTRACTION PRODUCTS
• Inefficient Solids Removal solids returned to the circuit
impact physical performance • Non standardized equipment and procedures to assess organic quality organic of poor quality returned to the
circuit detrimentally impacts performance; surfactants get re-dispersed into the organic as a result of mechanical breaking of emulsions
Organic Phase Contamination Small amounts of ‘bad’ organic can compromise the quality of the entire plant inventory. To demonstrate this phenomenon, organic from a commercial plant was recovered and added to fresh organic in varying concentrations. IFT and PDT measurements were taken for each resulting blend and appear in Figure 1 below. A 1% addition of poor quality organic was observed to double PDT directly impacting the dispersion band depth and proximity to the weir in the settler. As the % of poor quality organic increases, ∆IFT5% and PDT both
rise exponentially. Plants operating with large dispersion bands or pushing flowrates may run into severe issues with physical performance as a result of the plant organic becoming contaminated by even a small bad batch of organic.
Clay Dosage Requirements and IFT Curve The dosage of clay is often chosen based on operator experience and beliefs regarding the capacity of the filtration/ processing equipment. In reality, the required dosage to efficiently remove the organic impurities varies with the source of organic and the level of contamination. Sufficient clay needs to be used to remove impurities and restore interfacial properties. Construction of an IFT clay dosage curve (IFT as a function of the mass fraction of clay) in the laboratory, shown in Figure 2 below, is recommended to determine the expected improvement in IFT as a function of clay dosage. Although clay dosages at mass fractions between 0.1 – 1.0% are most commonly used in the industry4,5, often it takes 4% or more to achieve the full benefit of the treatment.
PDT (under organic connuity) . g r 250 o r y e 200 i d t n u u n150 ) c n e o100 s c ( T 50 D P
Delta IFT 4 )
m c 3 / s
198
e n d ( T 1 F I a t l 0 e D
2 y
133 30
76
0.0%
1.0%
0
2.5%
5.0%
Percentage of "bad" organic added to inventory
Figure 1 – Impact of “bad” organic on PDT and Delta IFT 38 37
IFT5%
) 36 m c / 35 s e n34 y d ( 33 T F I
IFT1%
32
ΔIFT5% = 6.1 ΔIFT1% = 3.2
31
IFT0%
30 0
2
4
6
Mass fracon of Clay (%)
Figure 2 - IFT as a function of clay dosage 10
8
10
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CYTEC INDUSTRIES | SOLUTIONS VOLUME 18
Figure 3 - Time for complete organic remediation at various clay dosages
Consumption of Extractant vs. Clay Dosage There is a conception in the industry that higher clay may remove active reagent and increase consumptions. This concern tends to be overstated. While there is some organic loss due to wetting of the clay, it is minimal. To verify, maximum copper loading was compared at a commercial SX operation without clay treatment vs. a “heavy”clay treatment at 5% mass fraction. The maximum copper loading was essentially the same for the two data sets (within experimental variability), indicating insignifi cant oxime lost through the “heavy”clay treatment.
Clay Deactivation The presence of aqueous within the clay treatment process deactivates the clay and prohibits the absorption of the interfacially active species. The organic being treated will often contain entrained aqueous. In some operations, organic clay treatment is carried out in the crud collection tank where signifi cant amounts of aqueous can be present. When clay is deactivated by aqueous, there will be little to no benefi t of the clay treatment operation.
Clay Dosage Infl uence on Organic Remediation Time The time required to restore the quality of a plant organic inventory will vary depending on the level of contamination, effi ciency of impurity removal, and volume of organic that may be treated per pass. Figure 3 shows an estimate of the
treatment time required for a specifi c SX plant. In this case using a clay dosage mass fraction of 1%, the organic quality will be 90% restored in 210 days. At 3% mass fraction of clay this time is reduced to 130 days and at 5% mass fraction of clay, it is reduced to 110 days.
ACORGA® CB1000 Clay Binder ACORGA CB1000 is a clay treatment process aid that improves fi ltration performance and allows operations to achieve higher clay treatment dosages through existing equipment. It works by collecting the fi ne particulates, making them easier to remove from the organic. In commercial applications utilizing a fi lter press, CB1000 reduces or eliminates the need to add Diatomaceous Earth (DE) in the body-feed. This frees up additional press capacity and allows for a higher clay dosage, without need to add fi ltration capacity. The higher clay dosage leads to the PDT and IFT benefi ts highlighted above. In addition, the organic treated in this manner is more clarifi ed, with fewer micro-solids returned to the plant inventory. This improves the physical operation of the plant by lowering crud formation and reducing entrainment. The results presented below were achieved at different SX plants using ACORGA CB1000 commercially. In those facilities, higher clay dosages were possible by replacing the diatomaceous earth (DE) body feed with ACORGA CB1000, which yielded noticeable improvements in organic clarity. Additionally, the higher clay dosage improved phase disengagement time and interfacial tension.
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CYTEC METAL EXTRACTION PRODUCTS
Sample w/ DE body feed (10,000 X ma gnification)
Sample processed w/ CB1000 (no body feed) (10,000 X magnification)
Figure 4 – SEM images - silver membrane filters post filtering of organic processed w/ DE vs. CB1000
Impact on Micro-Solids and Clarifi cation Improvement Figure 4 displays SEM images of fi lter membranes used to fi lter organic samples exiting a fi lter press. One sample was processed with DE as a body feed and the other one was treated with ACORGA® CB1000 at 500 mL/m3 (eliminating body feed). The pictures show particles remaining in the sample that had been fi ltered with DE while the organic which was fi ltered with CB1000 was essentially solids free. Figure 5 and Figure 6 compare the size of particles remaining in the organic after clay treatment for two plants who switched from DE to ACORGA CB1000. Prior to the change (Figure 5), Plant 1 data shows more micro solids (less than 6 µm in size) in the treated organic consistently throughout the batches. Plant 2 shows inconsistencies in the particle size distribution from batch to batch, suggesting variability in the fi ltration performance when using DE. After the switch to ACORGA CB1000 (Figure 6) both plants display more highly clarifi ed organic fi ltrates (smaller particle counts), as well as more consistency in fi ltration performance.
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Organic Q uality Improvement Figure 7 shows IFT measurements on samples collected from 2 commercial trials with and without use of ACORGA CB1000 at the same clay dosage to demonstrate equivalent organic quality. The average IFT improvement (measured by ∆IFT) as a result of clay treatment is similar between batches fi ltered with DE in the body feed to those treated with ACORGA CB1000 with no body feed. This indicates clay treatment using CB1000 is as effective in removing an equivalent amount of surfactant impurities as the conventional clay treatment process employing a body feed. However, when using ACORGA CB1000, eliminating DE in the body freed up suffi cient press capacity to double the clay dosage from 2% to 4% mass fraction of clay. The corresponding IFT measurements also appear in Figure 7, showing a higher ∆IFT by as much as 75%, resulting in an organic of better quality being returned to the process.
CYTEC INDUSTRIES | SOLUTIONS VOLUME 18
Conclusions Over the past decades, improvements in equipment design and plant practices have reduced organic entrainment losses, lowering the natural bleed of organic contaminants which cause plant performance issues. In addition to lower organic losses, SX plant design capacities are being exceeded in response to maturing ore bodies, declining PLS grades, and/or higher production requirements. The combined effects of these industry trends put a new emphasis on maintaining satisfactory plant organic quality through efficient clay treatment. Contamination of the plant inventory by poor quality recovered organic, even in small quantity, can have a drastic impact on phase separation and interfacial tension, leading to severe plant performance issues.
A number of deficiencies have been highlighted and suggestions made to improve the efficiency of this process. In particular, ACORGA® CB1000 Clay Binder has been developed and shown to solve many of the challenges faced in the clay treatment operation. Used as a processing aid, it allows for a more efficient clay treatment process.
Plant 1: Clay Treatment with DE
Plant 2: Clay Treatment with DE
) 10,000
) 10,000
8,000
8,000
l m / s e l c r a p ( t n u o C e l c r a P
l m / s e l c r a p ( t n u o C e l c r a P
6,000 4,000 2,000 0 4 < P > 6 µm
Batch 1(DE)
6 < P >1 4 µ m
Batch 2(DE)
1 4 < P > 23 µm 23 < P > 50 µm
Batch 3(DE)
6,000 4,000 2,000 0
P > 50 µm
Batch 4(DE)
4 < P > 6 µm
Batch 5(DE)
6 < P > 1 4 µm
Batch A(DE)
14 < P > 23 µm
Batch B(DE)
2 3 < P > 50 µm
Batch C(DE)
P > 5 0 µm
Batch D(DE)
Figure 5 - Particle Size Distribution of clay treated organic fi ltered using only DE body fi ll Plant 1: Clay Treatment with CB1000
Plant 2: Clay Treatment with CB1000
) 10,000 l m / s e l c r a p ( t n u o C e l c r a P
) 10,000
l m / s 8,000 e l c r a 6,000 p ( t n u 4,000 o C
8,000 6,000 4,000
e l c 2,000 r a P 0
2,000 0 4 < P > 6 µm Batch 1(CB)
6 < P >1 4 µ m
Batch 2(CB)
14 < P > 2 3 µ m 2 3 < P > 50 µm
Batch 3(CB)
Batch 4(CB)
4 < P > 6 µm
P > 5 0 µm Batch 5(CB)
6 < P > 14 µm
Batch 1(CB)
1 4 < P > 23 µm
Batch 2(CB)
2 3 < P > 50 µm
Batch 3(CB)
P > 50 µm
Batch 4(CB)
Figure 6 - Particle Size Distribution of clay treated organic using ACORGA CB1000 Plant 1: Interfacial Tension 34.0
DE in Body Feed
500 ppm ACORGA CB1000
Plant 2: Interfacial Tension 2.5
29.0
) 2 m c / s e 1.5 n y d ( T 1 F I a t l 0.5 e D
28.0
0
33.0
) m c / 32.0 s e n y 31.0 d ( T 30.0 F I
32.0
1.00
31.5
D is ch ar ge
D el ta I FT
)
0.80 m c
) m c / 31.0 s e n y d ( 30.5 T F I
/ s e y d ( 0.40 T F I a t l 0.20 e D
0.60 n
30.0 29.5
0.00 A(DE)B(DE)C(DE)D(DE)
F ee d
4% CT
2% Clay Treatment (CT)
A(CB)B(CB)C(CB)D(CB) F ee d
D is ch ar ge
A(CB)B(CB)C(CB)D(CB)
D el ta I FT
Figure 7 - Interfacial tension results from two commercial trials utilizing ACORGA CB1000 13
CYTEC METAL EXTRACTION PRODUCTS
References 1. Brueggemann, M. (2006). Advancements in organic entrainment reduction at the Phelps Dodge Tyrone SXEW plant. Sohn International Symposium Advanced Proc essing of Metals and Materials, Volume 7 - Industrial Practice , Kongoli, F. and Reddy, R.G. (eds). The Minerals, Metals & Materials Society, pp 501-507. 2. Giralico, M.A., Post, T.A. and Greaves, M.C. (1998). New mixer designs for the next generation of SX/EW mixer settler system. Proceedings of the SME Annual Meeting , Society for Mining, Metallurgy & Exploration, Littleton, CO, Pre-print 98-120. 3. Robinson, T., Sandoval, S. and Cook, P. (2003). World copper solvent extraction plants:Practices and Design. JOM, 55(7), 24-26 4. Mattison, P.L., Kordosky, G.A. and Champion, W.H. (1983) Enhancement of solvent extraction by clay treatment of contaminated circuit organics. Proceedings of 122nd AIME Annual Meeting - Hvdrometallurgy. Development and Plant Practice, Atlanta, USA.
5. Hutzler, B., Cooper, C., McCallum, T. and McCallum, A. (2015). Clay treatment improvements using ACORGA ® CB1000 clay binder. Proceedings of SME Annual Meeting, Feb. 2015, Society for Mining, Metallurgy & Exploration, Denver, CO.
14
CYTEC INDUSTRIES | SOLUTIONS VOLUME 18
High Performance Synthetic Copper Depressant Delivering Signifi cant Benefi ts to Cu-Mo Separation Process Qi Dai, D.R. Nagaraj
[email protected] [email protected]
Traditional Cu-Mo depressants used in Cu-Mo separation are hazardous inorganic chemicals. A mining operation in Inner Mongolia, China, consumes a large quantity of Sodium hydrosulphide (NaSH) in its Cu-Mo circuit. In 2014, the mine conducted industrial scale trials with a high performance synthetic organic reagent, AERO ® 8371 PNR, as a copper depressant. The application of AERO 8371 PNR resulted in about 45% reduction in NaSH consumption, and delivered a number of benefi ts to the mine. NaSH dust and stench were reduced in the reagent warehouse and reagent preparation workshop. Reduction in NaSH consumption resulted in up to a 35% reagent cost saving. Since the use of AERO 8371 PNR, molybdenum product grade has increased from 45% to 47%, and the copper content in the molybdenum product has decreased from 1.2% to less than 1%, a threshold to allow upgrading the molybdenum product to Class 1 from Class 2. This is achieved with a shorter cleaner circuit, 7-stages vs. 9-stages before the trial. Furthermore, the stability of the Cu-Mo circuit was improved, resulting in higher Mo recovery. The reduction in NaSH consumption has also benefi ted logistics and solved some operational issues. The risk of NaSH supply shortage and transportation burden are greatly eased. The reduced quantity of NaSH fl akes enables the mine to secure better quality of the raw material, which not only benefi ts Cu-Mo separation, but also helps eliminate the blockage of the NaSH solution delivery pipes.
Introduction A signifi cant portion of molybdenum is produced as a byproduct from porphyry copper ores. The small amount of molybdenite (MoS2) in these ores is fl oated along with copper to a bulk Cu-Mo concentrate. The concentrate is then separated by depressing the copper minerals and fl oating MoS2[1]. Sodium hydrosulphide (NaSH) (or sodium sulphide) is one of the traditional depressing reagents. In porphyry copper ore fl otation, Cu-Mo separation has long been a challenging process. This is especially true in Wunugetu mine, where Cu and Mo grades are low and proportion of secondary copper minerals are high. After the commissioning in 2009, the mine has implemented several technical modifi cations in the Cu-Mo circuit. The porphyry copper ore body has three million tons of copper and 600 thousand tons of molybdenum reserves, and is the fourth largest coppermolybdenum ore reserve in China. In 2010, the mine and a Research Institute completed a joint project in process optimization, which stabilized the Cu-Mo plant operation. However, the operation still faced three major challenges:High NaSH consumption (cost), environmental and occupational health concerns of the hazardous reagent and logistics of the
reagent supply. Moreover, high residual depressant in process water requires more aggressive treatment of recycle water, raising overall production cost. To solve these problems, the mine set a new target for improvement by searching for a reagent of better dosage-performance, lower toxicity and ease of handling.
Proven Performance with AERO 8371 PNR In 2013, the mine started to evaluate copper depressants. In 2014, following encouraging laboratory results, industrial scale trials were conducted with the best candidate, AERO 8371 PNR, a product of synthetic polymer family developed for sulfi de minerals depression. The mechanism of the polymeric chemistry and application examples can be found in published articles [2-4]. In principle, this chemistry works in conjunction with NaSH in a more positive pulp potential range than NaSH alone. As a result, the Cu-Mo circuit can operate at much reduced NaSH dosage. Now, daily NaSH consumption is about 45% less than before while the increased reagent cost of AERO 8371 PNR is only a fraction of NaSH cost saving. The mine also benefi ted from the introduction of AERO 8371 PNR in many other areas, details of which are presented below.
15
CYTEC MINERAL PROCESSING
Ore Characterization [5,6]
Experimental:Laboratory Cu-Mo Separation
The ore contains copper, molybdenum and other sulfi de minerals. The copper minerals are chalcopyrite, bornite, blue chalcocite, chalcocite, covellite and tennantite. Molybdenum occurs as molybdenite. Gangue minerals are quartz, muscovite, feldspar, illite, and kaolinite. Ore assays are shown in Tables 1 and 2. As seen, majority copper and molybdenum minerals are sulfi des.
Several laboratory experiments were performed on Cu-Mo bulk fl otation concentrate to fi rst study the feasibility of our reagents, and later to explore NaSH replacement ratio by the synthetic depressants to provide guidance for reagent plant trials. Two examples are provided below (Figures 1 and 2). They were obtained in rougher fl otation tests (about 10-min) at various NaSH and synthetic depressant dosage combinations. The ideal performance is to achieve as high Mo recovery and as low Cu recovery as possible (i.e. least amounts of Cu in Mo product/rougher froth). In the early experiments, Na2S was included in the tests and was confi rmed to have the same effect as NaSH.
Table 1. Ore assay ELEMENT
Mo
Cu
S
Fe
Pb
wt%
0.025
0.37
2.38
2.58
0.011
ELEMENT
SiO2
Al2O3 CaO
MgO
K2O
Na2O
Au (10-6)
Ag (10-6)
0.33
0.95
0.33
0.04
3.1
wt%
73.25 13.04
0.15
Zn
As
C
0.014 0.014 0.091
The current synthetic depressant technology cannot yet totally replace NaSH. However, as shown in Figure 1, certain combinations of NaSH/Synthetic depressant ( ) can achieve the same performance as NaSH alone ( ).
Table 2. Mineral phase 100
PHASE
COPPER MINERAL
MOLYBDENUM MINERAL
Cu%
Cu distribution%
Mo%
Mo distribution%
Sulfide
0.36
97.3
0.022
88.00
Oxide
0.01
2.70
0.003
12.00
Total Cu
0.37
100.00
0.025
100.00
Typical assay of Cu-Mo bulk fl otation concentrate is given in Table 3.
90 Starng point
80 70
% y r 60 e v o c 50 e R o 40 M
Perfect Cu-Mo separaon
30 20 NaSH/Synthec combinaon 10
Table 3. Cu-Mo bulk concentrate assay
NaSH
0 0
ELEMENT
Mo
Cu
S
Au (10-6)
Ag (10-6)
Wt%
0.93
26.97
31.8
0.1
65
10
20
30
40
50
60
70
80
90
100
Cu Recovery %
Figure 1 Results of lab tests (10-min rougher flotation; CuMo bulk flotation concentrate; NaSH dosage range: 15005700 g/t; Synthetic depressant dosage range: 0–1800 g/t)
16
CYTEC INDUSTRIES | SOLUTIONS VOLUME 18
Figure 2 shows the Cu-Mo separation results at varying % NaSH replacement levels. Better performance is those with higher Mo recoveries (▋)and lower Cu recoveries (). The fi gure indicates that 40%-50% NaSH replacement seems to be optimal based on the laboratory rougher testing. 100 90
% y r e v o c e R o M / u C
80 70 60 50
In this plant, over 80% of NaSH is added to the rougher and the scavengers (2-stage), which was not changed during the cleaner-trial. Therefore, the pulp in the cleaners was still loaded with NaSH, as seen by very reducing pulp potential. A question was then raised as to whether AERO 8371 PNR really played any role in depressing copper minerals. This was tested by not adding AERO 8371 PNR to the cleaners and this immediately resulted in copper fl oating in the cleaners and high copper in the fi nal molybdenum product. This proved that AERO 8371 PNR addition was critical to Cu-Mo separation.
Mo
40
Cu
30 20 10 0 0
41
51
61
69
NaSH Replacement %
Figure 2 NaSH replacement evaluation (NaSH dosage range:1600-5700 g/t;AERO ® 8371 PNR dosage range: 860–1170 g/t).
Plant Trial Set Up & Methodology There are two fl otation plants in Wunugetu mine, 1 and 2, both processing the same ore at a similar ore throughput. Some differences in the Cu-Mo circuit between the two plants are: • Finer grinding in Plant 2 than in Plant 1 • Column fl otation for the last four stages of cleaners in Plant 2, while other stages (including all stages in Plant 1) use conventional fl otation cells • Flotation cells are oversized in Plant 2 • More NaSH consumption in Plant 2 • Higher %Cu in molybdenum product in Plant 2 • Less stable operation in Plant 2
The full plant trial was started in Plant 2. After testing various combinations of NaSH/AERO 8371 PNR and dosages, the plant could not get consistent production of quality molybdenum product. Two problems were realized, a) the plant was very unstable for mechanical reasons, and pulp levels in every fl otation cells fl uctuated from below the lip to fl ooding;b) the columns (Cleaners 4-7) were not receiving suffi cient feed, thereby not producing froth. A decision was made to move the trial to Plant 1, where all stages were using conventional fl otation cells and the process was traditionally more stable than Plant 2. Within a week, the circuit was operating at the targeted NaSH replacement ratio while the AERO 8371 PNR dosage was being gradually optimized. At the same time, molybdenum product quality was showing the trend of improvement, i.e. decreasing copper content. Having achieved the trial objective in Plant 1, the mine decided to modify Plant 2 by placing the existing fl otation cells and columns with new cells of sizes with more compatible throughput along with some other changes. Three months later, Plant 2 was started under the new condition with NaSH/ AERO 8371 PNR. Today, the plant is operating in a more stable manner, producing better quality products at a higher molybdenum recovery than before.
The fi rst trial was conducted on a small scale, only in cleaners (7-stage) in Plant 2. Reagent dosing pumps were set up at every cleaner, although not all cleaners were dosed with AERO 8371 PNR at the later stage of the trial. This trial demonstrated that AERO 8371 PNR could replace about 50% or more NaSH (in the cleaners) without negatively impacting metallurgical performance of the Cu-Mo separation circuit.
17
CYTEC MINERAL PROCESSING
Advantages of NaSH/AERO® 8371 PNR Metallurgical performance The full plant trial in Plant 1 lasted about one month. Figure 3 shows Mo concentrate grade before ( o) and during ( ◆) the trial.
Table 5. Reagent consumption before (July) and during the trial (August)
60
e t a r t n e c n o c o M n i
% o M
Economics In addition to the value realized by molybdenum product upgrade, NaSH consumption is greatly reduced by the application of AERO 8371 PNR. Table 5 shows the reagent consumption for the pre-trial month (July) and the trial month (August).
50 40
Cu-Mo BULK CONCENTRATE TONNAGE INCREASE %
30 20 10 0
NaSH CONSUMPTION, TON
July
August
July
-
47.2%
735
August Reduction 463
272 (-37%)
AERO 8371 PNR DOSAGE, g/t July
August
0
374
7
e t a r t n e c n o c o M n i u C %
6 5 4 3 2 1 0
Figure 3 Mo concentrate grade before (o) and during ( ◆) the trial. Upper: Mo%, lower: Cu% Apparently, during the trial not only the Mo concentrate grade but also the operation stability was significantly improved. This led to the increase in the production of both copper and molybdenum products (Table 3). Table 4. Pre-trial (July) and trial (August) production numbers
MONTH
PRODUCT �WAREHOUSE SAMPLE� GRADE Copper
Molybdenum
PRODUCTION INCREASE% �AUGUST VS. JULY� Copper Molybdenum
Cu%
Mo%
Mo%
Cu%
July
19.883
0.270
45.39
1.33
-
-
August
19.331
0.302
47.10
0.93
39%
2.6%
Also to be noted, Cu% in molybdenum product is decreased to less than 1%, a threshold to allow upgrading the molybdenum product to Class 1, a category of a higher value than Class 2 (Cu%>1%).
18
In August during the trial, Cu-Mo concentrate processed in the Cu-Mo separation circuit increased 47.2%, but NaSH consumption was reduced by 37% to 463 ton from 735 ton. Although the new reagent AERO 8371 PNR was introduced, overall reagent cost during the trial month was reduced by over 30%. Using today’s production and cost numbers, higher cost reduction is being achieved due to higher NaSH replacement ratio, a simpler process and a greater stability of plant operation. Plant stability A number of factors contribute to the improved process stability: • Less frequent batch preparation of NaSH (flake) solution gives better consistency in solution concentration. • Lower consumption of NaSH makes it possible to secure supply of better quality of NaSH, which helps eliminate blockage of NaSH solution pipelines by impurities from poor quality NaSH batches. • Shorter cleaner circuit: Down to seven stages from nine stages. • More compatible equipment size with pulp volumetric flow. Better control of pulp level in each stage. • No need for dilution and no oxidation issue of AERO 8371 PNR allow for reliable and easy reagent handling.
CYTEC INDUSTRIES | SOLUTIONS VOLUME 18
Environmental Success of the introduction of AERO ® 8371 PNR has also brought benefi ts in environment. Nearly 50% less usage of NaSH fl akes leads to less shipping and handling of NaSH, resulting in: • Improved working environment by reduced exposure to NaSH dust and stench in the reagent warehouse and solution preparation workshop • Reduced risk of affecting air quality in downstream areas • Lower safety risk associated with road transportation of NaSH (down by 20 tons daily) • Less need for tailing water treatment
Conclusion Compared to NaSH, the synthetic reagent AERO 8371 PNR is a non-hazardous, easy to handle, and cost effective copper mineral depressant. Successful application of AERO 8371 PNR within the Inner Mongolia China mine has made signifi cant improvements in many areas, such as Cu-Mo separation effi ciency, metal recovery, production cost, circuit optimization, operation stability, environment/health and logistics of the reagent supply.
References 1. Ferrous-Metal Sulfide Mineral Processing , Hu, X.G., Ed., 1987,
Logistics Reduction of NaSH consumption has greatly eased the risk of supply shortage and associated impact on logistics planning and production. As a result of the improved supply security, the mine now has a greater fl exibility in procuring quality NaSH, which in turn contributes to the stability of the separation process.
Study of Residual AERO 8371 PNR in Water Residual AERO 8371 PNR in the tailing water from laboratory fl otation tests was analyzed for its possible impact on copper mineral fl otation in the bulk fl otation circuit. The fl otation tests were done using fresh water without NaSH. At the AERO 8371 PNR dosage of 1000 g/ton bulk concentrate, residual AERO 8371 PNR in the water, was found to be to be 0.6 ppm of the total dosage, or 0.6 g/ton ore which is insuffi cient to cause any detrimental on Cu in the bulk circuit. Normal AERO 8371 PNR dosage applied in production is well below 1000g/ton of ore. In the mine, tailing water from two plants was pumped to several tailing ponds, where dilution by other water sources also occurs. Water from the ponds is recycled to both bulk fl otation and Cu-Mo separation circuits. It is very diffi cult to estimate the amount of residual AERO 8371 PNR that enters the bulk circuit, but if any, considering the above, it will be well below the level for Cu depression.
pp.159-160, Metallurgy Industry Publisher, Beijing, China. 2. Nagaraj, D.R., Wang, S.S., Avotins, P.V., and Dowling. E, 1986, “Structure-activity relationships for copper depressants,” Trans. IMM, Vol. 95, pp. C17-26. 3. Nagaraj, D.R., Basilio, C.I., Yoon, R.-H, and Torres, C, 1992, “Mechanism of sulfi de depression with functionalized synthetic polymers. In:Proceedings of the 3rd International Symposium on Electrochemisty in Mineral and Metal Processing , R. Woods, P.E. Richardson Eds., May 17-22, 1992,
St. Louis MO, Vol. 92-17, pp. 108-128, The Electrochemical Society. 4. Nagaraj, D.R, 2000, “New synthetic polymeric depressants for sulfi de and non-sulfi de minerals,”. Chapter in Developments in Mineral Processing , Vol. 13, pp. C8b 1-8. 5. Yang, B.D., Yang, S.L., 2012, “Industrial experiment of coppermolybdenum separation,” Gold, Vol. 8, pp. 35-40. 6. Gu, Z.J., Wang, Y., 2009, “Feasibility study of coppermolybdenum fl otation”, Ferrous-Metals: Mineral Processing , Vol. 2, pp. 1-4.
19
CYTEC MINERAL PROCESSING
Application of AEROPHINE® 3418A Promoter at a Cu/Au Flotation Plant in Asia Peter Riccio, Vladimir Grujic Peter.Riccio@ cytec.com Vladimir.Grujic@ cytec.com
Introduction AEROPHINE® 3418A Promoter is a unique dithiophosphinate based collector that is highly selective for copper, lead, activated zinc and nickel sulphides, and precious metals. AEROPHINE 3418A Promoter exhibits strength yet, selectivity against iron sulphides (pyrite, pyrrhotite, marcasite, and arsenopyrite), non-activated sphalerite and many minerals which contain penalty elements. In addition, it has good toxicological properties. It is not considered as dangerous goods and not classified as a water pollutant. AEROPHINE 3418A Promoter has been most frequently used when treating massive sulphide ores, with fine grind and where its selectivity against pyrite and other iron sulphides is a major advantage. Recent work has shown that AEROPHINE 3418A Promoter can also offer benefits when used in lower pyrite, porphyry copper ores, where coarse grinds are typically employed. These findings resulted in commercialization of AEROPHINE 3418A Promoter at a major new Cu/Au operation in Asia where it has now been successfully used for over 2 years. Some of the advantages observed include high Cu and Au recoveries, ability to operate at lower pH (in comparison to less selective collectors), excellent plant stability, excellent plant
working conditions (no detectable odour and ease of handling), and acceptable treatment cost due to the very low dosage. This paper discusses the benefits of using AEROPHINE 3418A Promoter for this particular Cu/Au operation in Asia.
Proven Performance with AEROPHINE 3418A Promoter -> From Lab to Plant The main orebody of the mine is a typical porphyry deposit with chalcopyrite as the dominant copper mineral. Au occurrence is primarily in association with chalcopyrite and to a lesser extent as native gold/electrum and with pyrite. In the development stage of the project, a significant amount of testwork was conducted by various Metallurgical Laboratories and Engineering companies with the objective to determine the optimum collector. Numerous collectors were tested including different xanthates types (PAX, SIBX, SIPX, and SEX), thionocarbamates, monothiophosphates/dithiophosphates (AERO 7249, S-8761, etc.) and AEROPHINE 3418A Promoter. In this test work it was found that AEROPHINE 3418A Promoter showed the best performance, in terms of Cu/Au recovery/ grade.
68 83
66
81
64
% , y r 79 e v o c 77 e r u C 75
62 60 58 56
73 71
54 9.5
10.5
11.2
3418A 6g/t pH within Collector and dosage
9.5
10.5 TC 6g/t
11.2
52
9.5
10.5
11.2
3418A 6g/t
9.5
10.5
11.2
TC 6g/t
pH within Collector and dosage
*TC – thionocarbamate collector
20
Figure 1. Cu and Au Recovery for AEROPHINE 3418A Promoter vs. Thionocarbamate at different pH levels.
CYTEC INDUSTRIES | SOLUTIONS VOLUME 18
As an example, results of comparative testing of AEROPHINE ® 3418A Promoter and IPETC are discussed below. Figure 1 shows the recovery of Cu and of Au vs. pH, at fixed collector dosage (6 g/t). The results indicate that AEROPHINE 3418A Promoter achieved significantly better performance on Cu/Au recovery vs. the thionocarbamate collector at different pH levels, Figure 1. Cu concentrate grades are not shown, but were equivalent for both collectors. After confirming the results on multiple ore types, AEROPHINE 3418A Promoter was specified as the sole collector to be used for the plant start up. A simplified flowsheet of the plant process is shown below, Figure 2, and it includes SAG mill, ball mill followed by rougher flotation, regrind of rougher concentrate and cleaner flotation stages. Rougher/scavenger tails and cleaners tails both report to final tails.
Primary Grind (SAG + Ball Mill)
and experimental design support for metallurgical testing. Support continued in assistance with plant optimization and in geometallurgical testing, with specific emphasis on reagent optimization for future ores. Additionally, a superior frother was developed specifically for this operation to work well with AEROPHINE 3418A Promoter. The new frother gives faster kinetics superior coarse particle support and a superior froth structure whereas the previous frother gave a brittle and unsupportive froth which frequently collapsed. The new frother provides a stable, yet fluid, froth which breaks down well in launders and does build up in circuit. Behind the scenes our manufacturing teams have ensured consistent and high quality product. Our experienced Logistics team have ensured smooth, uninterrupted supply and the Product Stewardship group has provided important information on reagent handling. A second production line was commissioned in 2014/2015 at our W elland, Canada plant to ensure that more than adequate production capacity for AEROPHINE 3418A Promoter exists.
Concluding Remarks:
Roughers Flotaon
Regrind Mill
Cleaners Stage
Final Tails Final Concentrate
Figure 2. Simplifi ed Flowsheet After the start up of the mill, production ramp up was achieved very quickly. This was likely helped by the selectivity of AEROPHINE 3418A Promoter minimizing recirculating loads. Once early transition ores were worked through and clean sulphide ore was encountered, the metallurgical objectives were soon achieved. Plant results on Cu recovery by using AEROPHINE 3418A Promoter was in range 88-90% and on Au recovery was in range 75-80%, depending on head ore characteristics. AEROPHINE 3418A Promoter has proved to be a highly effective collector for coarse particles, considering the coarse grind utilized at the operation. Prior to start up and during the commissioning period, we provided on-site support by experienced Metallurgists. The support included operator, metallurgist and lab personnel training, circuit surveys, reagent dosage optimization, safe reagent handling recommendations
Mine sites and operators require more effective, specialized and selective reagents that recover not just the primary metal or mineral, but also the other co-value metals contained in the ore. AEROPHINE 3418A Promoter has demonstrated this capability on an ore type which is different to those which it is normally used on. It has proved effective in maximizing the recovery of Cu and Au, maintaining circuit stability and ease of operation, maintaining selectivity against gangue, achieved high recovery of coarser particles, including middlings. Treatment costs were kept low due to the very low dosage requirement. This is achieved with one of the safest, easiest to handle sulphide collectors available. AEROPHINE 3418A Promoter should be considered, for use as the sole collector, when developing the reagent suites for porphyry Cu/Au ores.
21
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22
100 Years Anniversary Employee Testimonials Shane Fleming, CEO "W e’ve been focused on the customers, understanding what they need from us to be successful, being willing to invest in innovation, developing new products, new processes that continue to create value for those customers and not taking those relationships for granted, understanding that we have a responsibility as a linear supplier to our customers to invest in their future."
Violina Griffin, R& D Manager, Mineral Processing "I think there are two main factors that contributed to Cytec’s continued success, the first one is the long term strategy focused on technical excellence and customer knowledge, the second one is the people; their expertise, their knowledge of the customer, their perseverance, hard work and dedication. I think these factors can also keep Cytec successful for the next 100 years."
Bob Cole, Business Development Director "I believe Cytec’s success is because of the partnership with our customers. Our customers can see the benefit and the passion that we bring to help them. These factors help to impact both companies positively."
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Disclaimer:Cytec Industries Inc. in its own name and on behalf of its affiliated companies (collectively, “Cytec”) decline any liability with respect to the use made by anyone of the information contained herein. The information contained herein represents Cytec’s best knowledge thereon without constituting any express or implied guarantee or warranty of any kind (including, but not limited to, regarding the accuracy, the completeness or relevance of the data set out herein). Nothing contained herein shall be construed as conferring any license or right under any patent or other intellectual property rights of Cytec or of any third party. The information relating to the products is given for information purposes only. No guarantee or warranty is provided that the product and/or information is adapted for any specific use, performance or result and that product and/or information do not infringe any Cytec and/or third party intellectual property rights. The user should perform its own tests to determine the suitability for a particular purpose. The final choice of use of a product and/or information as well as the investigation of any possible violation of intellectual property rights of Cytec and/or third parties remains the sole responsibility of the user. TRADEMARK NOTICE:The ® indicates a Registered Trademarkin the United States and the ™ or * indicates a Trademarkin the United States. The mark may also be registered, the subject of an application for registration or a trademarkin other countries. In Process Separation custinfo@ cytec.com tel: +1 973 357 3100 cytec.com/businesses/in-process-separation/mining-chemicals
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