INSTRUCTION MANUAL .

VIGERSLEV ALL 77 - 2500 VALBY - DENMARK 2040 AVENUE C - PA 18017-2188 BETHLEHEM USA CAPITAL TOWERS 180. KODAMBAKKAM HIGH ROAD, NUNGAMBAKKAM,- CHENNAI 600 034 - INDIA

BALL MILLS 70000375-1

Bolted-on lining plates

Erection Instruction

The text refers to the following instruction manuals etc.:

General safety regulations on erection sites

General Instruction. Operation and Maintenance

DucroBar lining for fine grinding chamber

DRAGPEB lining for fine grinding chamber

DUO3 lining for coarse grinding chamber

DUO3 lining for fine grinding chamber

STANEX diaphragm

Separately forwarded erection drawings

32031

70000393

9181

39031

38731

70000373

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Edited by: BjIJ Translated by: BjIJ Approved by: JVi MGN code: B601

Pages: 23

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Indhold: Side: 1. General information ......................................................................... 4 2. Construction and operating principle ................................................ 5 3. Erection ........................................................................................... 6

3.1 Preparations....................................................................................................................9 3.2 Fixation..........................................................................................................................10 3.3 Lining plates for inlet head (06).....................................................................................11 3.4 Shell lining for coarse grinding chamber (1), (8) ...........................................................11 3.5 Grates and lining plates for stanex diaphragm (app. lll)................................................13 3.6 Shell lining for fine grinding chamber (02) ....................................................................13 3.7 Outlet grate (13) ............................................................................................................14 3.8 Wet process mills..........................................................................................................15 3.9 Dismantling of worn lining plates...................................................................................15

4. Operation ...................................................................................... 16 5. Maintenance .................................................................................. 17 Appendix ........................................................................................... 18

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Appendices: Shell lining types I

Vertical lining and grates. Erection details II

Stanex diaphragm lll

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1. GENERAL INFORMATION

Lining plates are installed inside a ball mill, mainly to protect the mill body from destructive impact and wear. Further some of the lining plates are by their shape improving the grinding efficiency of the mill, and others, i.e. grates for diaphragm and outlet head, are screening the ground material and preventing the grinding media from leaving the chambers.

This instruction manual deals with the different types of bolted-on lining plates and grates used in a ball mill. For boltless and semi-boltless lining types is referred to separate instruction manuals.

The high-Chromium alloys used for lining plates and grates are materials with excellent characteristics in terms of hardness and wear resistance, whereas the impact resistance is limited. So because of the relative brittleness of these materials it is essential that lining plates and especially grates are handled with care during transportation and erection on site. The lining plates and grates must never be thrown about or hurled casually into a pile on top of one another since impact and pressure loads may cause the plates to crack. This is especially important for the thinner lining plates and grates of the fine grinding chamber. Further, grates and lining plates must not be subject to bending stresses when the bolts are tightened. However, correctly installed, lining plates and

NOTE !

The present instruction manual is concerned with the situations which, according to the experience of FLS, are the most likely to occur. An exhaustive enumeration of all conceivable situations which may occur during the erection, operation and maintenance of the equipment cannot be provided. Consequently, if a situation should arise, the occurrence of which is not foreseen in the instruction manual, and which the operator is/or feels unable to handle, we would recommend that FLS is contacted without undue delay for advice on appropriate action.

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grates manufactured from high-Chromium alloys will normally have a long service life compared to most other materials.

2. CONSTRUCTION AND OPERATING PRINCIPLE

Lining plates and grates are normally cast from wear resistant high-Chromium alloys, except for the inner lining plates on inlet head which are subject to heavy impact from the big balls of the coarse grinding chamber. These inner lining plates are made in the extremely ductile Manganese steel.

For the different mill types, different shell lining types and combinations of lining types are used. See appendix I.

Cement mills, type UMS: Step lining (1), bolted or semi-boltless, is used in coarse grinding chamber and semi-boltless corrugated lining (2) in fine grinding chamber. The same lining types can be used in cement- and slurry mills of type UM.

Raw mills, mono-chamber, types TUMS and TMS: Heavy, bolted classifying lining (3) with step lining (1) closest to the inlet head. The classifying section is a combination of wave lining and classifying lining plates. The same lining types can be used in raw mills types TUM and TM.

Coal mills, mono-chamber, type TM: Light, semi-boltless classifying lining (4) which is a combination of bolted classifying plates and boltless Dragpeb-plates, both with corrugated profile.

Most bolted-on shell lining plates for coarse grinding chambers are designed to fit to several mill diameters in a range. For that reason, the contact area at the bottom of the plates are manufactured with two different radii. So depending of the actual mill diameter, the contact to the mill shell will be an area along the centreline of the plate (for the largest mill diameter in the range) or outside this centre area (for the smaller mills).

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The vertical lining plates and grates, i.e. lining plates for inlet head, grates and lining plates for diaphragm and grates or lining plates for outlet head, are more or less of the same design in the different mill types. See appendix ll and III. The main difference is that lining plates and grates for coarse grinding chamber are of a heavier design than those for fine grinding chamber due to the impact from the big balls.

Vertical lining plates and grates are normally installed with two or three bolts and there must be contact to the mill body only with the contact faces around the bolt holes.

Besides protection of the mill body, the function of the shell lining is to lift the ball charge sufficiently high to give the required power uptake. But on the other hand, the lining -at least in coarse grinding chamber- must not lift the ball charge too much since this will give higher impact loads on the lining plates, resulting in crushing and increased wear on lining plates and balls.

Lining plates and grates for coarse grinding chamber may normally be used together with balls up to 100mm in diameter. In fine grinding chamber, the maximum ball size is 60mm.

3. ERECTION

COMMAND:

Directions in instruction No. 32031, General safety requirements on erection sites have to be obeyed on site.

The instruction must be read by client, erection company and supervisor before the erection starts.

When the instruction says:

ERECTION CONTROL

it means that the responsible erection chef or supervisor have to control and accept the erected parts before the erection can continue.

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SAFETY:

Whenever work is being done inside the mill, on top of the mill or under the mill, the main motor MUST be de-energized by switching off the high- voltage switch and LOCKING it. When the auxiliary drive is engaged, this too has to be locked. Only the responsible work coordinator/ shift manager must be able to remove the lock.

Due to the safety of the personal there must, during the whole erection, be stable scaffolding and platforms including hand rails wherever needed.

Safety helmet and safety shoes must be used on site.

Working gloves are highly recommended when working with lining plates.

Dust protection masks to be used when necessary (e.g. during cleaning). Hearing protection to be used whenever using noisy tools (e.g. grinding machines, jack hammers or pneumatic keys). When grinding or flame cutting protection glasses must always be used.

When lining plates are installed there is always a risk that they, if wrongly handled, are falling down and thereby represents a danger for injuring of personal. Therefore measures must to be taken to make all lifts safe.

Weights of grates and lining plates can be found in the parts lists.

When the mill is turned no personal is allowed inside, on top of or under the mill.

During the erection of lining plates and grates, the mill can often become unbalanced (side-heavy). Turning a side-heavy mill is very critical and the mill must therefore be secured by use of wires and chain blocks to prevent the mill from rotating unintentionally. The wires with chain blocks can be bolted to the mill shell through one or more lining plate boltholes and anchored to the floor with expansion bolts. Building columns must not be used for anchoring.

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If the mill is turned by means of the auxiliary drive and this is equipped with an over-running clutch, the installation of lining plates must always be done so that the side heaviness presses in the right direction on the over-running clutch. Otherwise there is a considerable risk for sudden, unintentional release of the clutch, with uncontrolled turning of the mill as result.

For use of electrical tools and working lamps plus General safety regulations at erection sites see FLS-instruction No. 32031.

IMPORTANT! During handling and erection of the heavy lining plates and grates, be careful not to drop these parts onto the unprotected mill shell. Impression marks will leave stress concentrations so high that there is a considerable risk for developing of cracks in the dynamically loaded mill shell.

DO NOT weld or flame-cut on the mill shell since such damages may also result in developing of cracks.

When lifting the lining plates into the mill through the manholes, be careful NOT to damage the edge of the manholes. In order to prevent damages, the edge of the manhole could be provided with a protection frame made from wood or angle iron.

In case the mill shell is damaged in some way, it must NEVER be repaired by welding, but only by careful grinding to obtain a smooth surface. FLS must be informed before any repairs are done.

Any superfluous bolt holes in the mill body (shell, slide rings or mill heads) MUST be closed by means of glued-in conical rubber plugs. Bolt holes must NEVER be plugged by welding since such welding will leave stress concentrations big enough to develop cracks.

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With the exception of welding specifically indicated on drawings and in instruction manuals no welding, nor repair welding, must be performed on the mill body unless prior approval has been obtained from FLS.

Whenever turning the mill during erection of the lining parts, it is of vital importance to lubricate the mill bearings to avoid seizure. So the high-pressure oil pumps must therefore be running during turning.

Whenever the mill is turned during erection, there should be no loose lining plates inside, since there is a risk for damage of the mill shell (if unprotected) or lining plates, or plates might drop out through a manhole

3.1 Preparations

As previously mentioned, it is very important that lining plates and grates are not subject to major bending stresses when the bolts are tightened, since the hard but relatively brittle materials may then crack. So lining plates and grates must have contact to the support (mill shell, slide rings etc.) only with the foreseen contact faces around the bolt holes.

So the entire inside surface of the mill body on which the lining plates and grates are to be fitted must be examined carefully for irregularities, i.e. weld splashes, too high convexity of weld seams etc., which may prevent proper contact between lining plates and mill body. Any such irregularities must be removed by careful grinding in order to obtain a smooth surface. Finally the mill must be completely cleaned for all dirt and waste.

Since many of the lining plates are very heavy, up to approx. 150 kg, it will normally be necessary to install suitable lifting equipment inside the mill, such as chain blocks, winch, trolley etc.

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3.2 Fixation When the lining plates and grates are to be installed, it must be checked that they are supported only on the contact surfaces around the bolt holes. If this is not the case, a minor adaption of the plates can be done by careful grinding. Such grinding must be done in a manner so as to prevent local heating, which may cause cracks.

It is especially important for grates and lining plates fixed by three bolts, that all three contact surfaces are in contact with the support.

Under no circumstances adaption of lining plates and grates by means of welding or flame cutting is allowed.

Due to different circumstances such as nominal clearance between lining plates and grates, casting tolerances and bolt clearance, there is a risk for rather big gaps between the plates. In order to distribute the plates evenly on the surface and to prevent them from twisting, most lining types are designed with small recesses on the backside. Wherever possible, the supplied spacer angles must be placed in these recesses. In case there is still more than 2mm gap after spacer angles have been inserted, weld on small plate pieces of different thickness to the angles.

Before mounting of the bolts, check the condition of the thread of all bolts and nuts and lubricate the thread with oil and molybdenum disulphide (Molykote or similar) to ensure minimum friction.

All lining bolts going through the mill body, i.e. with nuts on the outside, must be installed with special sealing washers to avoid leakage of material. The sealing washers consist of a machined washer with increased bore (10), a rubber grommet (11) inserted in this bore and on top a normal washer (12). Since the rubber grommet is thicker than the machined washer, the rubber will be squeezed into the clearance between bolt and hole when the nut is tightened, thus forming a seal.

The lining bolts must be tightened to a specified torque, by means of a torque spanner, and they have to be retightened until the torque remains constant.

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During the tightening process, the bolts are to be vibrated by blows from a hammer on the head.

For tightening torques and re-tightening, see drawing No. 3.021665.

Bolts which have the nut inside the mill must be secured by tack-welding of the nut after the final re-tightening.

3.3 Lining plates for inlet head (06)

The inlet head can be either plane (in mill types UMS, TUMS, TMS, TUM or TM) or conical (in UM mills). In both cases, the lining plates are designed with contact faces around the bolt holes. These faces must be the only contact between the lining plate and the mill head. In order to distribute the lining plates evenly on the surface with uniform spaces between the plates, insert spacer angles (07) wherever possible in the recesses on the backside of the lining plates. The bolts must be able to pass freely through the holes and must be parallel to the mill axis.

The relatively heavy lining plates must be lifted into the mill through the manhole by means of a small electrical winch or a chain block. Inside the mill the lining plates can be handled by pulling/pushing them on steel plate or boards up to the inlet end. When placed near the inlet head, also use an electrical winch or chain block to lift the plates up in position. Whenever the mill is turned during erection, there should be no loose lining plates inside, since there is a risk for damage of the mill shell (if unprotected) or lining plates, or plates might drop out through a manhole.

This paragraph (3.3) is also valid for erection of lining plates on outlet head in TM mills (fully airswept).

3.4 Shell lining for coarse grinding chamber (1), (8)

For type of shell lining to be used in the relevant mill, see separate erection drawings for mill and lining. Also for identifying the different lining patterns and find out where to install them in the chamber, please study the assembly drawings.

In case of semi-boltless lining, see separate instruction manual.

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Fully bolted-on step lining in cement mills (UMS) are normally supplied with rubber backing (09). Make sure that the individual rubber plates do not interfere with each other or fold, since such increased thickness of rubber will result in improper contact between the lining plates and mill shell. The plates must lie firmly against the mill shell without tilting. Otherwise the mill shell or contact face(s) must be adapted by grinding. Insert spacer angles, wherever possible in the recesses under the lining plates.

Step lining plates must be installed so that the thin end of the plate is pointing forward in the direction of rotation of the mill (05).

In UMS mills, the first row of lining plates at the inlet head is boltless. This first row is fixed by the outer lining plate on inlet head and the first bolted-on row on the mill shell. The rubber plates under the two first rows of lining plates must is extended to cover the corner (radius R20) of the slide ring. To prevent the boltless lining plates from moving in circumferential direction during operation, 70x70mm locking plates must be placed in the corners between the boltless plates and the first bolted-on plates. When the bolted rows have been installed, the boltless plates must be aligned in both directions in relation to the bolted-on plates and the supplied shims must be inserted, wherever required, in the circumferential and longitudinal gaps between the plates. Use as few and as thick shims as possible and fix them firmly in the gaps by hammering. (see the lining erection drawing).

Erection control

The last row of bolted-on lining plate at the diaphragm must be erected only after the outer boltless lining plates (22) of the Stanex diaphragm have been installed.

The mill has to be turned two or three times in order to erect a full lining ring. Do not erect too may rings simultaneously, since the mill will become unbalanced (side-heavy) with the risk of uncontrolled turning.

The lining plates inclusive rubber backing for the manhole covers should be installed outside the mill and only lifted into the mill when needed.

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The fully bolted classifying lining (03) in raw mills, types TUMS and TMS (and TUM and TM) has no rubber backing

3.5 Grates and lining plates for stanex diaphragm (app. lll)

See separate mill erection drawing and instruction manual Stanex diaphragm.

Grates (20) and lining plates (21) must not be subject to bending stresses when the bolts are tightened. Therefore they must rest only on the surfaces around the bolt holes. This is especially important for the grates since they are fixed with three bolts. In case of insufficient contact, it is necessary to either align with shims or by means of careful grinding so that all contact faces have full contact with front plate and supporting plate.

It is important that the grates and lining plates evenly distributed over the diaphragm surfaces, i.e. with uniform gaps between them, and that the bolts are perpendicular to the diaphragm. The grates and lining plates are fixed with shared, through-going bolts. The bolts holding the grates and lining plates are partly square head bolts (23) used at the radial butt joints and partly bolts with conical seating (B-bolts)(24) used in the central hole in the grates. First the B-bolts (24) are erected through the grates, diaphragm structure and one of the holes of the lining plates with washer and nut. Under the head of the square head bolts a square washer (25) must be used. However, as the grates do not necessarily have the same height it may be necessary first to insert half square steel washer(s) (26) to level out the difference. The maximum allowable height difference between two adjoining grates is 0.2 mm. When all the bolts (23 and 24) have been installed with washer and nut, and the grates and lining plates are evenly distributed over the diaphragm surface, the bolts must be tightened to the specified torque (See drawing No. 3.021665). The outer boltless lining plates (22) have to be erected at the same time as the shell lining in chamber 1.

3.6 Shell lining for fine grinding chamber (02)

Different types of semi-boltless linings for fine grinding chamber are available, both corrugated and classifying.

For erection of these, see the relevant instruction manual.

However, all the above mentioned precautions to take in connection with erection of bolted-on lining plates are also valid for the bolted-on plates of a semi-boltless lining.

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3.7 Outlet grate (13)

The structural parts (supporting plate) (15) for outlet grates have normally been finish-assembled in the workshop. Before starting erection of the grates, it must be checked that the supporting plate has been properly aligned, i.e. is concentric with the shell and firmly fixed to the web plate of the slide slide ring. It is extremely important to check now that the supports for the grates, i.e. the pipes and the flat bars, are completely flush within the area of each grate, so that the grates are not subject to bending when the bolts are tightened.

Erection control

If not done already, adjust the lifters of the supporting plate to full length.

Before bolting on each grate, it must be checked that all three contact faces on the backside are in contact with the support. In case of insufficient contact, it is necessary to adapt the grate (or support) by careful grinding.

In order to distribute the grates evenly on the surface, with uniform spaces between the plates, insert spacer angles wherever possible in the recesses on the backside of the grates. The bolts must be able to pass freely through the holes in the grates, in the supporting plate and the slide ring, and must be parallel to the mill axis.

The bolts holding the grates are partly square head bolts (15) used at the radial butt joints and partly bolts with conical seating (B-bolts)(16) used in the central hole in the grates. First the B-bolts (16) are erected through the grates, supporting structure and slide ring web plate with sealing washers and nut. Under the head of the square head bolts a square washer (17) must be used. However, as the grates do not necessarily have the same height it may be necessary first to insert thin half square steel washer(s) (18) to level out the difference. The maximum allowable height difference between two adjoining grates is 0.2 mm. When all the bolts (15 and 16) have been installed with sealing washers and nut, the bolts must be tightened to the specified torque (See drawing No. 3.021665). The outer boltless lining plates (22) will be erected at the same time as the shell lining.

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For mills with central drive, sealing washers for the bolts are not required, but just normal washers, and after final retightening, the nuts must be secured by tack-welding.

Erection control

3.8 Wet process mills

In principle, lining plates and grates are to be installed in the same way as for dry process mills. However, as slurry penetrates under the lining plates and will cause wear and corrosion on the mill body, it is extremely important that all lining plates bolted-on to mill shell and heads are installed on rubber sheet.

Depending on type of semi-boltless lining in fine grinding chamber, such a lining can either be installed on rubber sheet or it can be grouted with a cement grout after the erection has been finished.

All major spacings behind lining plates must be filled with soft rubber blocks in order to prevent slurry from sliding / rotating, thus causing wear on the mill body.

3.9 Dismantling of worn lining plates

In worn-out lining plates, the bolt heads are normally so deformed that it is impossible to dismantle the bolts from the plates in a normal manner. Since the bolts cannot be re-used after all, the recommended procedure is to unscrew the nuts and remove the lining plates without taking out the bolts.

Only if it is impossible to unscrew the nut, it should be considered to cut off the bolt end with nut by flame-cutting or with a cutting disc, or by melting away the bolt head by means of carbon electrodes (air-arc gouging). If the latter methods are used, utmost care must be taken not to damage the mill body (shell, slide rings etc.). Cutting scars in the dynamically loaded mill body will most likely result in developing of cracks sooner or later. Such scars must be carefully smoothened by grinding and inspected for cracks and futher be inspected for cracks in the future twice a year. DO NOT repair scars or other damages by welding. Also note that scars and grinding of said can make it very difficult to seal the boltholes again with new seals.

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For grates and lining plates for Stanex diaphragm and other lining plates where the nuts have been tack-welded, either the head or nut has to be melted/cut-out by means of flame-cutting or air-arc gouging.

NOTE! It is a highly dangerous job to dismantle worn lining plates, especially semi-boltless liners, since there is a risk that plates may fall out unintentionally. So ALL safety precaution must taken to avoid any injuries on personnel working in or around the mill.

If the worn lining plates are dropped to the floor on top of each other through the manholes, there is a considerable risk of flying debris which can be very dangerous. Proper measures have to be taken to avoid injuries.

When the lining plates have been loosened, it is essential that the worn lining plates do not drop down on unprotected mill shell or damage the edges of the manholes when they are taken out of the mill. Protect the mill body from damages!.

4. OPERATION

Before charging the mill with grinding balls, check that all lining parts are correctly installed and that the bolts are tightened with the prescribed torque. Remove tools and other remains from the erection from the mill.

IMPORTANT!

In order to avoid damage of lining plates and grinding balls, there MUST always be a suitable amount of materials (clinker or limestone) in the coarse grinding chamber before charging the grinding balls and starting the mill. The amount of materials should be approximately 25% of the weight of the grinding balls.

It is essential for the lifetime of the lining plates that the mill is always operated with sufficient material. If the amount is too small the lining plates and the grinding media will be worn much too fast and there is a considerable risk of breaking the

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lining plates and the grinding media in the coarse grinding chamber. When stopping a mill, the feed to the mill should not be stopped more than 2-3 minutes before.

All lining bolts which have the nuts inside the mill, must be re-tightened, with torque spanner, first after 2 hours of operation and then every 12 hours until the torque remains constant. Then secure the nut by tack-welding. Lining bolts which have nuts outside the mill body, must be re-tightened, first after 8 hours of operation and then every 12 hours until the torque remains constant. These nuts must not be tack-welded.

Erection control

Any material/dust leaking from the mill during operation must be stopped immediately. Besides contamination of the mill building, leaking material may result in wear of the mill body.

5. MAINTENANCE

For maintenance of mill lining, please refer to General Instruction. Operation and Maintenance

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Appendix

I Key to enclosures l

01. Step lining

02. Corrugated lining

03. Classifying lining for coarse grinding chamber

04. Classifying lining for fine grinding chamber

05. Mill direction of rotation

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I

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II

Key to enclosures ll

06. Lining plates for inlet head

07. Spacer angle

08. Shell lining

09. Rubber backing

10. Machined washer

11. Rubber grommet

12. Normal washer

13. Grates for outlet head

14. Supporting plate

15. Square head bolt

16. B-bolt

17. Square washer

18. Half square washer

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II

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IIl Key to enclosures lll

20. Grates

21. Lining plates

22. Outer lining plate

23. Square head bolt

24. B-bolt

25. Square washer

26. Half square washer

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IIl

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