Raw Material Presentation

It is a Iron Ore Palletizing Plant at sohar –

Capacity: 2*4.5MTPA 13636 T/Day 568.16 T/Hr

Sultanate of Oman

Technology: Grate Kiln {formerly known as Allis-Chalmers Kiln} Brief: Pellets are transforms of Mineral resources of superior quality feed feed as raw materials to D.R.I & Blast Furnace process For Steel making……

Raw Material: Iron ore, Limestone, Anthracite &  Bentonite. Fuel: Natural Gas

Vale’s Industrial Empire Vale Oman Palletizing Plant

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Process capability Stimulate Process Performance Prepare Process Plan

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Vale Oman Palletizing Com Complex:Process Control Dept.

Vale Oman Process Flow Chart Feed

Thickener

Bentonite

Iron Ore Additives Chips/Chunks

Fuel

Drying

Mixing

Grinding

Balling P H 2

Rotary Kiln

Annular  Cooler 

P H 1

T P H

D D 2

Traveling Grate

D D 1

Roller  Feeder 

CONTENTS:Define : Process Control Glossary of Terms & Methods of preparation: (Sampling) Raw Material Handling: ( Sampling of Iron ore , Lime stone, Anthracite) Grinding Area: ( Sampling of feed to mill & mill discharge feed) Mixing & Blending Area: ( Sampling of Mixed material & Bentonite ) Thickener Area: (Sampling of slurry ) Balling Area: (Sampling of Green Ball ) Traveling Grate Area:( Area:( Sampling of Feed to T.G , Discharge material of T.G Measurement of Temperature, Differential Differential Pressures and Process Gas flow) Rotary Kiln & Annular cooler Area: ( Measurement of Kiln Feed end, Middle, Discharge Temperatures, Gas Flow , Stack sampling sampling & Sampling Sampling of finished finished product) Product Coating Area : ( Sampling of coating material ) Health & Safety Information: Vales Motto

Define : Process Control : The Fundamental philosophy associated with the economic production of  Pellets must be based on defect PREVENTION rather then defect DETECTION. This approach requires a system of PROCESS CONTROL, which can only be effectively implemented through STATISTICAL TECHNIQUES. Decisions to modify or adjust processes must be based on statistical evidence, such as control chart data. Reliance Reliance on INSPECTION for quality control is both ineffective ineffective and inefficient.

Glossary of Terms & Methods of preparation: (Sampling) TERMINOLOGY USED IN SAMPLING AND SAMPLE PREPARATION

Finished Products indicated to be of the same category and offered Lot: The quantity of Raw material/ Finished for inspection at one time. A lot may consist of the whole or a part pa rt of the quantity ordered for. Sub-lot: The quantity of ore/pellets in each of the pa rts into which a lot is divided for the purpose of  sampling. Increment: The quantity of ore/pellets obtained by a sampling device at o ne time from a lot or sub-lot. Unit Sample: The quantity of ore/pellets collected at one time from the conve yor (Unit sample is larger  than the increment). Gross sample: The total quantity of ore/pellets consisting of all increments or unit samples taken from a sub-lot. Size sample: The sample taken for the the determination of the size distribution of the lot or sub-lot. sub-lot. Moisture sample: The sample taken for the determination of moisture content of the lot or sub-lot. ore/pellets obtained by reducing a gross sample following a Laboratory sample: The quantity of ore/pellets specified procedure for determining chemical composition of a lot or sub-lot. Composite sample (For the lot): The quantity obtained by mixing together propo rtional quantities of  ore/pellets representing the mass of each sub-lot which a lot has been divided. Sampler: Person responsible for performing the sampling operations. Sampling method: That part of the sampling procedure dealing with the method prescribed for withdrawing withdrawing samples.

Random sample: Sample in which the different fractions of the material have an equal probability of being represented. represented. Representative sample: Sample obtained according to a sampling procedure designed to ensure that the different parts of a batch or the different properties of a non-uniform non-uniform material are proportionately proportionately represented. Sampling plan: Description of the location, number of units and/or quantity of material that should be collected, and associated acceptance criteria. Sampling procedure: The complete sampling operations to be performed on a defined material for a specific purpose. A detailed written description of the sampling procedure is provided in the sampling the sampling protocol . Sampling record: Written record of the sampling operations carried out on a particular  material for a defined purpose. The sampling record should contain the batch number, date and place of sampling, reference to the sampling protocol used, a description of the containers and of the materials sampled, notes on possible abnormalities, together with any other relevant observations, and the name and signature of the inspector.

Need for Sampling: Introduction : According to ISO/IEC 10725, “sampling” is defined as “a procedure whereby whereby a part of  a substance, material material or product is taken taken to provide for testing or calibration calibration a representative representative sample of  the whole. Sampling may also be required by the appropriate specification for which the substance, material material or product is to be tested.” tested.” In other words, the the goal of sampling is to select and and obtain a test portion of of the material in some manner, such that the sub-sample is representative representative of the larger amount of material. Sampling is often a major source of error and if a truly representative sample of the batch is not obtained, then the subsequent analysis will give a wrong figure. It is the aim therefore to develop correct sampling protocols, considered to be an essential requirement for obtaining valid results within Prospect.

100% Inspection of Process Output is an unsatisfactory method to determine product quality. It is costly ,has no relationship to future quality, and is impossible in many cases. Sampling reduces the cost to measure Product quality and can be used to predict Future product quality when used in Conjunction with control charts.

Samples must be taken so that their results are representative of actual process quality .In other words, they must be taken So that the results are unbiased.

SAMPLING: The methods of collecting increments or unit samples from a lot may be classified into following types or a combination of below mentioned. Sampling from conveyors. Shipment sampling. Stockpile sampling. Sampling during production. Automatic samplers. Sectional sampling. Trench sampling.

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 ts Pelle ts

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Sampling from conveyors: When ore/pellets is moved on conveyors, one of the most reliable methods of manual sampling is stopped belt method. Whenever it is practicable to stop the conveyor belt  periodically, a large quantity of iron ores known known as unit sample may be drawn by stopping the belt. The sample shall be collected from the full width and thickness of the ore/pellet stream over a suitable length of the conveyor. In case it is not possible to stop the conveyor the sample shall be taken from a specified  place on a conveyor or at a specified transfer point of conveyor.

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Shipment sampling: In order to get gross sample, the ore/pellets shall be sampled as far as possible when in motion. That is from the conveyor during loading or immediate immediate discharge during unloading at regular interval.

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Stockpile sampling: The ore/pellets from stockpiles shall be carried out as far as possible, when they are in motion, that is, during the formation of the stock piles or during the shifting of the stockpiles to the other places. Sampling from the stationary stockpile shall not be conducted, as this would introduce significant bias in sampling.

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Sampling during production: The ore/pellets shall be collected as per stopped belt method from the conveyor or at the convenient discharge point of the conveyor.

Trench sampling: Along a randomly chosen line on the ore surface of the sub-lot, a trench shall be dug, right down to the ground level leaving about 0.3 meter  walking space at the the ground level. From the the trenches so dug, the required number  number  of increment shall be collected with the help of suitable sampling scoop, scoop, at various points points randomly spread over over the two exposed sides sides of the trenches. In case of large stockpiles, in addition to the trench, the sides of the piles may also  be opened to expose the ore down to the th e bottom, at places where the trench does not expose the ore inside. Automatic samplers: In Grinding Section & Product pellet area, the automatic samplers have been provided. By simple button pressing at the required req uired interval the sample will be collected. Sectional Sampling: 4 unit samples in the case of fines and calibrated ores and at least 8 unit samples in the case of sized ore and lumps are to be collected from each sub-lot. For this purpose, the requisite number of points shall be chosen at random on the entire surface of the stockpiles. At each of the selected points, a circle of suitable diameter (minimum three times the largest particle size) shall  be marked. The material over the area of this circle and along entire height of the stockpile from top to bottom shall be collected in stages. This can be done by taking initially initially ores up to a depth of 50 cm and covering the hole so formed by a  plate for removing the the ores lying on the the sides of the hole. Then after removing the plate further depth can be reached in the same manner and the ores can be collected from the freshly formed hole.

SAMP SA MPLE LE PR PREP EPAR ARAT ATIO ION N •

Before analyzing any raw material for Physical/Chemical/Metallurgical properties it is very important to mention here about the sampling and sample preparation. The sample should be collected which is a well representative of the total raw material ready for dispatch and well prepared before analysis. In order to collect representative sample for correct analysis, sampling and sample preparation is a very important tool for preparing a sample for analysis.

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The primary object of sampling of any material is to draw an inference about the quality of the lot on the basis of information derived from the sample. If the consignment is of uniform nature the inference so drawn is almost precise, which gives an accurate estimate of the quality, but when the material is heterogeneous in nature as is often the case with any raw material, the method by which a sample obtained becomes critical in inferring about the quality of the consignment.

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The efficiency of sampling largely depends on the degree of homogeneity of the material and size of the sample. In case of heterogeneous material, the size of the sample should be more for accurate estimate of the quality.

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Preparation of a final sample for physical, chemical and metallurgical properties is an important aspect, because the sample prepared in accordance with the below mentioned procedure will fetch accurate analysis otherwise erratic results.

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There are different methods of sample preparation.

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Riffle divider

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Coning and quartering.

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Reduction by Riffle divider: The final sample shall be well mixed and poured into the the riffle. This process shall be repeated using different sizes of  riffles according to the size of the ore.

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RIFFLE SAMPLE DIVIDER : IS : 1607, IS : 2720.

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Efficient sampling out of bulk materials/deposits is the most important for getting the true idea about the bulk material. The volume of  material to be tested is usually usually quite huge and it requires reduction in volume in a methodical methodical manner. The Riffler Sampler (sample divider) helps to reduce the bulk while maintaining the character of the material and thus it is a helpful, light and handy device for sampling work. The standard units are made of GI sheet and mounted on rigid steel frame and supplied with three pans and one scoop.

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Standard Chute sizes are 25mm, 18mm and 12 mm. However, the Chute sizes can be made according to the user's specifications etc.

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shaped pile. Care Coning and Quartering method: The ore shall be well mixed and then scooped into a cone shaped shall be taken to drop each scoopful exactly over the same spot as otherwise the central axis of the cone will be slackened and an uneven distribution of lumps and fines will result.

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After the cone cone is formed formed,, it shall shall be flatten flattened ed by press pressing ing the the top of the cone cone with with the smooth smooth surf surface ace of the the scoop. scoop. Then it is cut into quarters by two lines which intersect at right angles at the center of the cone.

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The bulk bulk of of the sam sample ple is redu reduced ced by by rejecti rejecting ng any any two diag diagona onally lly oppos opposite ite quart quarters ers

Coning

Process Process Control Control - Raw Material Material Sampling Sampling Tools Tools :

Process control: Instruments for Monitoring Temperatures , Differential Pressures , Gas Flows & Level Sensors

T H E R  M O C O U P L E S

F L O W M E T E R  S

P R  E S S U R  E G A U G E S

B E D L E V E L S E N S O R  S

Raw Material Handling systems: ( Sampling of Iron ore , Lime stone, Anthracite) •

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In general, general, for any any industr industry y a right right amount amount of of input input is necessa necessary ry to produce produce an effe effective ctive outpu outputt as yield. yield. In In our pellet pellet  plant we are getting the iron ore fines as the input from Brazil through shipment, shipment, we need an handling system for  transporting of the raw material from Port area to our plant, and hence we are making use of equipments like Stackers, Reclaimers & Conveyors for serving the purpose. purpose.

Raw material unloading from ship VESSAL CAPACITY: 4 .0 LAKHS TONS UN LOADER CAPACITY : 10,000 T/H

Unloaded Iron ore stocked near Jetty area

(Iron Ore Stockpile) Stacker &  Reclaimer Capacity:10,000T/Hr

Iron ore Piles near Jetty Of  Capacity: 946.000T

Iron ore Stockpile capacity: 766.000T

Limestone & Anthracite Stockpiles

Limestone Stockpile Capacity:6.000T

Anthracite Stockpile Capacity:15.000T

Process Control Sampling Plan: •

Vale Oman has Raw material’s Storage capacity capacity of 1712.000T( Iron ore),where sampling is challengi challenging ng task to meet the Homogeneity Homogeneity of the sample. Process Control Dept. aims to execute such a difficult task where there is a higher degree of confidence in the source then sample.

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Two Two typ types es of sampl samplin ing g err error orss are are poss possib ible le:: a) Segregation errors This occurs when particles are exposed to gravitational, rotational, vibratory or  aeration operations (or other types of mechanical motion), usually resulting in fine  particles migrating to the bottom and larger particles being concentrated at the top. This type of error is thus dependent upon the previous history of the powder and usually occurs with free or easily flowing flowing powders, having a significant range of   particle size. This type of error can be minimized by suitable mixing and building up the sample from a large number of increments.  b) Statistical errors This is type of error is caused by observing a sample instead of the whole lot. Although this type of error cannot be prevented, it is likely that the size of statistical errors can generally be controlled by taking a large enough random sample from the entire lot.

Process Sampling at Stockpiles

Random sampling of entire area

We need to trench the entire the pile , so as to have uniformity &  homogenization in sampling

Dividing the Entire Mass in to Layers a Composite sample has to be drawn.

10 Mtrs

Top Layer

Middle Layer

Bottom Layer

Stocked Raw materials are transported through conveyors in to Plant Storage Bins:-

Continuous visual Monitoring has to be followed so, as to identify contaminations

Random Sampling of raw materials on conveyors:Sampled Raw materials are tested for moisture (M%) ; Size Distribution with the support of Quality control Depts. If there are any abnormalities, we can control at initial stages…………Later stages…………Later raw materials materials are stored in to Day Bins to meet the rated capacity of plant/day. Samples to be taken from Weigh feeders: AL: 2105.01-06

Grinding Area: ( Sampling of Feed to Mill & Mill discharge feed) Hot Gas Generator

Ball Mill Capacity:424TPH

The term H.G.G refers to Hot Gas Generator used to remove moisture from the mixed raw material (Iron ore, Lime stone, Anthracite) before it enters grinding mill , Grinding refers to the size reduction of a material by tumbling it in a revolving cylinder. There are two types of grinding processes (1) Vertical and (2) Horizontal. But we are using Horizontal grinding process. This occurs when the ore and a grinding media are tumbled together. The grinding media used are Hi-Chrome Steel balls. These balls are of different diameters distributed through out the Ball Mill. The media method of size reduction depends primarily on impact or compression fracture of the ore caused by the impact action of heavier steel balls. Such impacts caused by the impacts or point-to-point contacts contacts occur between the ore and the balls or between the balls and the mill shell liners. It is important that the balls are large enough so that as many points of contacts as possible occur and sufficient impacting action is provided which will result in the proper breaking of the ore particle.

Grinding Media

Mill Diaphragm

Mill Liners

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The grinding mill liners are provided with lifters. As the mill cylinder is rotated the lifters lift the balls to give them a proper cascade pattern and the energy to do breaking. The cascade pattern is determined determined by the rotating speed of the mill cylinder and the mill diameter. The energy consumed in grinding is therefore proportional proportional to the weight of media, the diameter and rotational speed of the mill.

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The size of the ball media media is determined by the size of the incoming feed particles. Larger sized ore requires require s a larger ball size for good impact efficiency. As the ore is gradually reduced size, the media itself wears out and the balls are reduced in size. These smaller balls are also necessary, as these balls are still adequate in size to cause fracture because many more points of contact occur and many more balls are present per unit volume. It is imperative to add bigger size balls for two reasons.

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To keep up the number of bigger size balls to break the large ore particles.

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To maintain the required number of balls in the mill to provide the power required for grinding. The media should be added as and when required as the balls are continuously being worn away.

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Another mechanism of size reduction that occurs in the mill together with impact grinding is abrasive grinding or attrition grinding grinding or grinding by rubbing as the ore particles and media slide and rub against against each other as the ball mill rotates.

Dimensions D=6.6M L=12M •

The patterns, which generally exist, are: -

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Cascade Pattern – Here the lifters lifts the balls giving them them the proper cascading cascading energy for   breaking up the ore initially.

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Impact Pattern - Once the balls lifted up and after attaining attaining a definite height it falls down down on the ore creating fractures. More the intensity of the balls finer be the size reduction.

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impact grinding, here due due to rubbing / Attrition Pattern – This takes place along with the impact sliding of the ore particles and the media against each other, size reduction takes place on the mill rotation.

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The The dis disch char arge ge of the the bal balll mil milll pass passeed thr throu ough gh the the SEP SEPOL OL a Dyna Dynam mic sepa separa rato torr to to separate the fine particles from coarse particles, it acts as a classifier. The separated coarse particles are recirculated to mill for regrinding.

Make Polysius

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CRITICAL SPEED OF BALL MILLS: ØCRITICAL SPEED: IT IS THE LOWEST RPM WHICH WHICH WILL CAUSE AN INFINI TELY SMALL PARTICLE ON THE SHELL LINER TO CENTRIFUGE.

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ØBALL MILLS ARE NORMALLY OPERATED AT 70  – 75%  – 75% CRITICAL SPEED.

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ØCRITICAL SPEED: [RPM] = 76.63 / √ D Where D is the Internal Internal Diameter Diameter of of mill in feet, measu red inside shell liners Types of circuits used in the Mills: Single Mill Primary as Single Mill Primary as Twin Circuit Single as Twin circuit Types of Grinding Media: Steel Balls Rods Pebbles Types of Grinding Mills : Rod Mills Ball Mills Pebble Mills

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Process Sampling At Ball Mill Area Sampling of Feed to Ball Mill for Moisture% & Size Distribution

Live load test to be carried on AL2111.01/2112.01/2113. 01

Sampling of Mill discharge for Moisture%, Blain .No, Size fractions

Fig:-001

Automatic Sampler: Apart from manual sampling as showed in fig:-001, Automatic sampling units units are also facilitated in Vale Vale Pellet Plant for sampling purpose in Grinding Area.

Air Slide Sampler

A sample is extracted when a hollow tube with a longitudinal slot rotates into position against the material flow. The sample falls directly through through the tube and into a sample bottle. This is specially designed to extract dry, non-sticky, bulk solid powders on a continuous or intermittent basis from air assisted conveyors

Dimensions: W x H x D/mm = 340 x 660 x 240 Sample collecting container volume = 51

Mixing & Blending Area: ( Sampling of Mixed material & Bentonite )

Paddles

Intensive Mixer Make:Lodige capacity: 650 T/Hr Length:5 Mtr Dia:1.85Mtr

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Mixer Mixer is is provi provided ded for for mixing mixing of of iron iron ore conc concent entrat ratee & bentoni bentonite te on cont continu inuou ouss basis. basis.

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Ploughsh Ploughshare are shovel shovelss rotate rotate in special special arrangem arrangement ent alon along g the horizonta horizontall shaft shaft inside inside a horizont horizontal, al, cylindrical cylindrical mixing drum. The size, number, positioning, geometric shape and peripheral speed of the mixing elements are coordinated for three-dimensional movement of the components inside the mixing drum. The resultant turbulence, with constant, total product mobility caused by the mixing elements, prevents the formation of dead or static zones and results in gentle, precision mixing within the shortest possible time.

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Mixing Mixing elements elements lift lift produ product ct during during radial radial movement movement from the the wall wall of of the drum thereby thereby preven preventing ting  particles from becoming squashed between the wall and the shovel. The hurling and whirling  process is, therefore, highly suitable for mixing processes in which the components co mponents have widely differing bulk bulk densities, particle sizes, rheological features features and – relevant to pharmaceutical pharmaceutical

Process Sampling Mixing & Blending Area: Feed Rate of  WF’sAL3112.01,02 Bentonite Sampling for Moisture% Grind% &  Swelling Index

Sampling at Mixer Discharge for Moisture% , LOI &  Chemical analysis.

Thickener Area: (Sampling of slurry ) Diameter: 30 m²area

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Thickener Arms

Thickenin Thickening g is a process process of reducing reducing the liquid liquid conten contentt and thereby thereby increasi increasing ng the soli solid d density density within within the the slurry. slurry. The mechanism is all based on the settling rate. The settling is even controlled by the rotation of the rake arms. The rotation of the rake arms makes the denser particles to be dragged to the central portion and the light particles move to the periphery. Almost clear water is taken as the overflow. Thickener is essentially a conical tank like structure. It has a central shaft at the axis of the conical tank. The rake arms are attached to a sprocket sprocket that rotates about the central shaft. There are four arms, two long and two short, all 90° apart. The longer arms are responsible responsible for the settling action. The shorter arms mainly deal with the central portion. But the central area is a denser portion subjecting more torque on the arms. arms. The shorter arms handle such denser matter reducing the torque on longer  arms.

Process sampling at Thickener area

Slurry Sampling at Thickener under flow for Density & % of  solids checking as per ISO:2591

Random Snap-cuts of slurry samples has to collected diff.intervals to have uniformity in sample

Automatic Sampling System –ISO-3082(2000) CBBS extracts a representative representative sample sample from the falling flow of material off a belt conveyor. It’s carriage-mounted carriage-mounted cutter traverses through the material flow, collecting the product sample as it goes, before discharging it into a hopper positioned outside the material flow

CBBS – Cross Belt Belt Bucket Sampler  Sampler 

Mounting may be in chutes, hoppers, at belt-end or head chutes. When activated, a slotted sample tube enters the product stream with the slot facing down. While full y extended, the sample tube rotates 270 degrees, taking a representative sample through the product stream. The sample tube then retracts out of the product stream, into the sampler housing and deposits the sample into the discharge. The sample tube can be driven  pneumatically or hydraulically. In our process Cross Belt Samplers are provided at conveyor  TR.3113.01 & TR.3123.01 -Mixing & Blending Area to Balling Feed. Sample will be collected at - CT.3113.01 . Capacity : 2.5kgs & feed rate of conveyor: 900Tph .Samples are collected in a box later carried to Quality Lab manually.

Palletizing Disc Area: (Sampling of Green Ball )

Agglomeration: As the Mixed Material is fed to the Balling disc, it gets lifted upwards due to the rotation of  the disc. The material gets lifted up as long as the friction between the ore particles and the disc bed is more than the gravitational force. Once the gravitation force on the ore particles is more than the frictional force, the particles roll down. As the particles roll down, they agglomerate. The agglomeration of the particles continues as long as the rolling movement is sustained, resulting in formation of the balls.

Technical details of Balling Discs : The palletizing discs consist of a flat circular base with a wall perpendicular to the plane of the base along the circumferences. Scrapers are provided on the base and side wall for deflecting the material. The disc is inclined at angle greater than the angle of response of the feed material and is rotated in this plane with a variable speed drive. The scrapers are fixed 1 position and do not rotate with the disc. • Inside Diameter: 7500 mm • Rotat Rotation ion Speed: Speed: 5 - 10 rpm • Feeding Capacit Capacity: y: 150 – 180 TPH TPH

Mechanism of Ball Formation: Factors effecting Balling:spraying

Inclination of Balling Disc

rolling up drying/solidifying

Disc Speed Feed Rate Moisture content powder powder seed

binder droplet

liquid bridges

solid bridges

Sidewall height Powder layering

Surface Area of the Particle

Spheronizing Granule

Green pellet

 „

snowball“-structure

Spheronizing of Wet Granules

Principle of Agglomeration Agglomeration

Green pellet

Process Sampling at Palletizing Discs Area Checking of Ball formation in discs BL-3131.01-07 BL-3131.01-07

Green Ball Sampling for Moisture % , Size fraction , Drop. No , G.C.S

G.C.S – Green compression strength

Green Ball Drop test

Traveling Grate Area:( Sampling of Feed to T.G , Discharge material of T.G, Measurement of Temperature, Differential Pressures and Process Gas flow)

Brief: The traveling grate is used primarily to dry and preheat green balls for feeding into the rotary kiln, where they are indurated. The traveling grate provides the means for efficient heat transfer with high, medium and low temperature gases. These gases transfer heat by convection so intimate gas solids contact is required for effective heat transfer.

Dried green balls do not have the physical properties necessary to survive direct feeding to the rotary kiln and must be semi-indurated. For acceptable semi-induration, it is necessary for green balls to be substantially heated and fluxstone fluxstone carbonates (if used) to be substantially calcined. calcined. Good gas-solids contact is required to cause cause bonding to occur and to remove CO2 CO2 so that calcination of the fluxstone fluxstone can proceed at reasonable rates. This semi-induration semi-induration or preheating is accomplished by flowing flowing the gases exiting the annular cooler and rotary kiln through through the bed of dried balls in the tempered preheat and preheat zones zones respectively of the traveling grate.

Process Sampling at Traveling Grate Checking Gapping of Roller Classifiers CS3131.01-07 & Roller Feeder AL3131.01

Checking the Bed Height, Sampling of feed to T.G for Moisture% & Size fraction

Process Measurement of Temperatures , Differential Pressures & Gas Flows

Process Control Monitoring of Profile Pr ofile Deviation……

External view of  Traveling Grate

Internal view of  Traveling Grate

L =68.80 Mtr

298.90M² 298. 90M² Area

W = 4.716 Mtr  

Bed Bed Level Level checkin checking g

Analyzing of Process Parameters Temperatures & Differential Pressures & Gas Flows, at Indurations Duct, Wind Boxes, Heating zones ,Stack sampling etc……….

Rotary Kiln & Annular cooler Area: ( Measurement of Kiln Feed end, Middle, Discharge Temperatures, Gas Flow & Sampling of finished product ) Dia: 6.9 Mtr  Length:45Mtr 

Rotary Kiln

Kiln Burner flame & Red Hot Pellets Discharge from Kiln

The rotary kiln is a downwards-sloping downwards-sloping cylinder from the traveling grate to the annular cooler. The speed of rotation controls the rate of solids flow through the rotary kiln and imparts a mixing action to the pellet burden. The mixing action is important because it creates a homogeneous homogeneous pellet product. All of the pellets are exposed to the burner flame for an equal amount of time. This residence time is sufficient to uniformly indurate all pellets, thereby minimizing the ball-to-ball quality differences inherent in pellets discharging from the static bed processing typical of a SG. At the discharge end of the rotary kiln is a single burner, which utilizes the hot recuperated (secondary) air from the annular cooler for combustion. The burner can be designed to fire a single fuel or a combination of fuels. Oil, Natural gas (LBG/Coke (LBG/Coke oven gas/ BF gas/ Corex Corex gas) or coal can be be used singly or in varying mixtures. mixtures. Because of the single burner, burner, controlling the induration induration process is a simple temperature temperature loop. Grate-Kiln plant processing Hematite Hematite ore may have few additional burners in pre heating zone. This is very different from a SG system that may require up to 50 burners.

Process control Monitoring Kiln Temperatures & Pressures & Burner Flame & Stack sampling

81 M² Area Area Annular Cooler

The annular cooler is functionally the same as the traveling grate except for its annular configuration. Hot  pellets discharging from the rotary kiln are distributed in the annular cooler as a level bed. Ambient air is forced upwards through the conveying elements (pallets) and the bed. Thus machine parts are not exposed to high temperatures.

Sectional view of Annular cooler  Inspection & Sampling of Product Pellet at TR3154.1-02 &TR3154.03-04

The pellets are leveled in the annular cooler to a bed depth of 700 mm and conveyed over up to 4 cooling zones. In each cooling zone, sufficient cooling air is  provided to produce the mass of air at a temperature required by the rotary kiln and traveling grate and . The various cooling zones are designed in such a way that they will recover the maximum heat from the hot pellets and various ducts carry this hot air to rotary kiln/ traveling grate zones and Ball Mill . Cooled pellets discharge through the cooler’s discharge hopper at a controlled rate to a product load-out system.

Automatic Sampling System –ISO-3082(2000)

The HEAD sampling equipment samples pellet from the end of of a belt conveyor. conveyor. This product collects accurate representative representative samples when mounted on the end of a belt conveyor carrying the product. Sampler installations are designed  per application. When activated an electric motor drives the slotted sample cutter through the product flow to collect a sample of the material. The sample is discharged via gravity to a sample collection point. Sample collection is initiated in r esponse to either an operator’s manual command or a signal automatically generated by controller logic, usually time-based but which could also  be volume or quantity based. In our process Head Samplers are provided at conveyor  TR.1010.12 & TR.1010.13- Product Pellet Carrying Conveyor at Transfer tower CT-1010.10&CT-1010.11.Capacity : 6.5kgs & feed rate of conveyor : 750Tph.Samples are collected in a Sampling box later carried to Quality Lab manually.

Product Coating Area : (Sampling of coating material )

Depending on customers requirements the finished product is coated to avoid Sticking of pellets in the further reduction process. To avoid such conditions Pellets are coated with external additives like Limestone or Dolomite with Bentonite acts as binder, together called as oxide coating of pellets. Pellets are coated with a additives ratio 5:1 of Limestone to Bentonite. Role of Process control is to monitor the Process variables like: Checking additives blend ration Flow rate ~ Tonnage Checking Pulp Density & % of Solids ( approx: 1.15gm/cc & 22 % solids) Maintaining the Product Pellet Moisture to 1.5 % max .

Pellet Stockpile of  Capacity: 3,80000 T

Stockpile sampling of pellets

Proce rocess ss cont contro roll Qual Qualit ity y Cont Contro roll

C.C.R C.C.R Monitor Monitoring ing

Health & Safety Information: Vales Motto Health and Safety Information The following list of safety precautions precautions should be considered as a guideline: Personal safety: Use all PPEs applicable while while working in the area (Safety (Safety helmets, Safety boots, boots, hearing protection, protection, Goggles, masks, masks, gloves etc). Use protective clothing appropriate to the work being performed. Work area safety: Maintain and practice good house keeping, keeping, which can prevent lots of imminent accidents Allow only authorized personnel inside. Operate the equipment controls with cl ean hands. Make daily check of starting alarms and warning devices and ensure the equipment is working properly. Examination of interior atmosphere for toxic etching, asphyxias or flammable components. Stairs, passageways, aisles, hallways, walkways, walkways, working areas and all emergency exit routes provided with electrical lights. Equipment safety: Follow caution signs and warnings Follow manufacture recommended work pr actices Check all equipments equipments before starting and give it it a change incase it asks for. Skilled supervision is required. Use all the rotating machinery provided with appropriate protection devices such as coupling guard as well as emergency stop buttons. Equipment must be locked out prior to removal of equipment guards. Electrical safety:  Never assume a electrical line to be dead unless it is t ested and declared so. Lockout and tag electrical /mechanical controls before performing any inspection, maintenance, lubrication. Any work on electrical installations to be carried out in accordance with safety instructions. Installation, maintenance maintenance and repair r epair of electrical equipment to be done when permitted by authorized persons. Sparks from electrical equipment (cable, wire, motor, hose etc) if observed to be reported to shift supervisor and maintenance department to be notified immediately.

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Conveyor safety: Ensu Ensure re the the con conve vey yor hor horns ns func functi tion on pro prope perl rly. y. Ensure Ensure convey conveyor or zero zero speed speed switch switch functi function on proper properly. ly. Stop Stop the conv conveyo eyorr when when there there is a need need to pass pass anyth anything ing ove overr it or under under it. it. Pers Person onne nell mus mustt neve neverr ride ride on on the the conv convey eyor or bel belts ts.. All walkwa walkways ys alon along g the the conv conveye eyed d must must be free free of mat materi erial, al, tools, tools, oil or grea grease. se. Ensu Ensure re all all pul pulll chor chords ds func functi tion on prop proper erly ly.. Loos Loosee clot clothe hess sho shoul uld d not not be be worn worn nea nearr con conve veyo yors rs.. Do not not lea lean n over over th the conv convey eyor or whi while le tak takin ing g sam sampl ples es If the the convey conveyor or main mainten tenanc ancee is to be taken taken,, make make certa certain in the the equip equipme ment nt is locked out according to the electrical lock out system and a work permit has to  be obtained prior to work commencing. To ensur ensuree safety safety,, have have the the equipm equipment ent cont control rolled led by by the loca locall field field contr control ol  panel. Safety training: All shou should ld be aware aware of of plant plant desig design n philo philosop sophy hy and and poten potentia tiall hazard hazards. s. All grades grades of pers person onnel nel must must be be invol involved ved in elab elabora oratin ting g emerg emergenc ency y  procedures. Report Reporting ing all unsaf unsafee cond conditi itions ons to their their super supervis visors ors.. Iden Identi tifi fica catio tion n of of dang danger erou ouss mate materi rial al and and are areas as.. Iden Identi tifi fica catio tion n of haza hazard rdou ouss subs substa tanc nces es.. Iden Identi tifi fica catio tion n of proh prohib ibit itiv ivee and rest restri rict cted ed area areass. Firs Firstt trai traini ning ng and and eme emerg rgen ency cy prep prepar ared edne ness ss.. Issu Issuin ing g of Safe Safety ty work work perm permit its. s.

Gas safety: Carbon monoxide is highly toxic when inhaled, it acts by combining with hemoglobin of  red blood cells to form carboxyhaemoglobin. This results in ox y-hemoglobin y-hemoglobin dissociation and oxygen transport in blood. An individual can work safely for 8 hrs in a 500-ppm exposure of CO gas. At high concentration of 0.4% i.e. 4000 ppm CO can prove fatal in less than an hour. Respiratory Protective equipments (RPPE) should be used in personal emergencies emergencies for  evacuation purposes and during clean up of the area.

For exposure protection against CO hazard use, Oxy-Breathing Oxy-Breathing apparatus. Compressed air breathing apparatus. Trolley mounted SCBA set. Air supplied blower facemask. Incase of a gas exposure, Remove the person immediately from the contaminated area to fresh air location and keep him comfortably warm. Tight fitting clothes, shoes and the belt of victim should be loosened. Inform OHC, Safety, Transport, and Utility for necessary action at their end. Incase of gas leaks, All sources of ignition should be kept away.SCBA to be used while sampling and attending leaks. Incase of fire, Dry chemical Powder and CO2 extinguisher extinguisher are suitable to fight small fire of CO.In case of large fire brigade should be called to attend the fire call.

Presentation By: A.Srik@nthKaundiny@ A.Srik@nth Kaundiny@ Process Control Dept. V@le Om@n Pellet Plant – Sohar-Sultanate of Om@n