This commentary is from USAK’s Energy Review Newsletter
http://www.turkishweekly.net/energyreview/TurkishWeekly-EnergyReview9.pdf
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On February 24, 2000 I visited the Orhaneli Mine with Mr. Clark A. Moseley, The North American Coal Corporation, USA. This is our joint report.
The Orhaneli Mine supplies lignite to the 210 MW Orhaneli Thermal Power Plant. In addition, the mine supplies lignite to the local populace for domestic purposes. The mine started production in 1979. About 1986 and 1987 the major equipment was purchased to produce the current production levels. However, the Power Plant did not reach full capacity until 1997 after the installation of Flue Gas Desulfurization units. The production for the past five years is as follows:
The mining license for the operation of the Orhaneli Mine covers 9143.88 hectares or about 22,600 acres. The license is intersected in the middle of the Gumuspinar mine area by a private license. The lignite field is divided into three areas, namely Gumuspinar, Sagirlar and Civili. All mining is in the Gumuspinar area, which is about 5 kilometers long and 1 kilometer wide.
The geologic structure is comprised of one main seam overlain by marls, sandstone, siltstone, mudstone and tuff. The lignite follows the floor of the basin and is somewhat flat in the center and steeply dipping (15 to 20 degrees) on the edges. The lignite seam is split into two with a parting layer approximately 0.5 to 1.5 meters thick. We were not able to see this parting layer in the pit nor was I able to review any drillhole logs to verify this parting thickness. The parting is completely mined with the lignite seam. Average lignite quality for all three areas is shown below:
At the start of 2000 TKI estimated the remaining lignite reserve to be 42.2 million tons. The Gumuspinar field contains 25.3 million tons, Civili has 10.7 million tons and Sagirlar has 6.2 million tons. This is TKI’s estimate and whether this estimate is quantified as mineable or at a certain quality cutoff is suspect. At the projected plant requirement of 1.4 million tons per year the current life of the Gumuspinar field after TOR transfer in 2001 is less than 17 years. The remaining production for the life of the TOR must come from either Civili or Sagirlar.
The overburden thickness in the Gumuspinar field ranges from less than 40 meters to over 170 meters and dips from the west to the east. Attached are conceptual cross sections of this field. Per current estimates the average mining ratio in this field is 14.5 cubic meters waste to 1 ton of lignite. I have not verified this estimate, but I believe that it is a fair representation of the current mining ratio. Local engineers have developed a reserve estimate of the Gumuspinar field and this estimate is summarized below:
We have included in the above estimate what we believe is the private lignite block or pillar that intersects this field. This block contains a substantial amount of lignite in the shallower up dip portion of the reserve.
The mining method used by TKI is a truck/shovel prestrip with the final uncovering of the lignite by a walking dragline.
The truck/shovel fleet is comprised of 4 P&H 1900 10 cubic yard shovels; 2 Marion 191M 15 cubic yard shovels; 27 Caterpillar 777 85 ton trucks and 13 Komatsu HD 785-A 85 ton trucks.
The dragline is a 33 cubic yard Bucyrus Erie 1260W.
The majority of this equipment was purchased new in 1986 and 1987. A more complete list of the equipment is shown below:
The pits are oriented along the strike and are proceeding down dip. The truck/shovel fleet removes the overburden down to a depth of about 26 meters above the lignite seam. The dragline then uncovers the lignite seam in an extended bench operation. Mining panels are about 70 meters wide for the dragline operation. The dragline spoils its material up dip. At the present time the dip of the lignite was stated to be 10 degrees. Most of the truck/shovel overburden is hauled to out of pit dumps. The highwall is planned to stand at 60 degrees and the spoil 30 degrees.
To produce approximately 1.4 million tons of lignite, the Orhaneli Mine employed 605 people as of October 1999. Of this total 96 are staffs which may not accept a transfer at the time of transfer date. The workforce is comprised of 509 employees which includes supervisors.
Mine Visit Observations
After discussions with the newly appointed General Manager, a tour of the mine, truck dump, shops and warehouse was conducted. On initial inspection, this operation is typical of all the state run mining operations in Turkey. Facilities are built along the same concept with the administration building, cafeteria, shops, and warehouses in separate buildings as part of a campus concept. Facilities are average in appearance and show neglect of normal maintenance. The landscaping shows neglect and is unkempt.
The active pit was idle at the time of our visit. This is normal during the winter months in Turkey. All operations in Turkey believe that operations during the winter months are difficult, if not impossible. The majority of the workforce stays at home and receives full pay during this time. However, a stripping contractor was operating removing overburden with 20 ton highway type trucks and was hauling to the outside dumps.
The pit had experienced a major spoil slide in the North end of the pit. Placing dragline spoil up dip on a 10 degree slope with little or no water control caused the spoil to slide back into the pit and cover up the exposed lignite seam. This spoil failure appeared to be an ongoing problem in that a pillar of virgin overburden was left to help buttress the slide. This effort has failed. The contractor will be used to re-handle the slide material and pillar to help stabilize the pit and to uncover the lost lignite. We could not tell whether any truck/shovel spoil had been placed on top of the dragline spoil in this area. I believe that all truck/shovel material has been hauled to the outside dump.
Very little of the lignite seam was observable. The pit had filled with water and no efforts at that time were being made to pump the water out of the pit. Although this region had experienced some snowfall and rain recently, the majority of the water in the pit is from groundwater seepage. However, the highwall was making some water, but it was not a significant amount. Proper water control management was lacking in both the active pit and on the spoil benches. The water in the bottom of the pit and in the active spoil contributes greatly to the spoil stability problems that the mine is experiencing.
Lignite loading operations are performed by the smaller shovels and wheel loaders. We also believe that the 45 ton trucks are tasked to haul the lignite. As stated in the geology section above, there exists a substantial parting in the lignite seam. If this parting is as described, then we believe that this parting could be effectively separated. The lignite in the run of mine stockpiles is of varying quality but shows evidence of considerable dilution from this parting and spoil. Due to the poor spoil stability, some of the lignite is also lifted by the dragline, which also contributes to the reduction in lignite quality. Quality can be improved by controlling the spoil, dewatering the pit and separating the parting. I was able to observe the top of the lignite seam, which the mine was saving for domestic sales and it looked like a very good, high quality lignite. Too bad it was not being saved for the power plant.
Prestrip operations appeared to have ceased. The highwall appeared to be very stable and was quite steep with little or no advance in front of the dragline. I was pleasantly surprised about the stability of the high wall. The lack of prestrip operations supports the premise that TKI has reduced its advance stripping while awaiting the TOR process. All of the shovels were sitting on the dragline bench. One of the Marion shovels appeared to be undergoing a major maintenance project. One of its tracks was missing. I could not see any active maintenance activities happening on any of the equipment parked in the pit. One blast hole drill was operating.
The overburden waste dump was being developed for the next vertical lift. As with all Turkish operations the waste dumps seemed to be lacking in planning and layout. Dumps were placed and shaped without any logic or long term plan. The active dump was driven at the slope of the ramps and was in an arc so that the dump maintenance would be minimal. However, this procedure exposes the trucks to a steep dump slope which is a safety concern. The preferred method would be to drive the ramp upward at the slope of the ramp, then expand the dump by dumping on the level. This would eliminate the trucks dumping an a slope that is at an angle to the axis of the truck and also eliminates added maintenance on the hoist cylinders and body pins.
We were able to get up on the dragline. It appeared that all power was off on the machine. With the freeze and thaw cycles that happen during this time of year, this could cause problems with the electric motors and generators as the machine is idled. The interior of the dragline was clean and well maintained.
We observed 5 Cat 777 trucks with their engines removed for maintenance. One of the trucks was parked on the dragline bench. Maintenance practices were very shoddy on this truck. The bolts, nuts, parts and accessories were scattered all over the truck and on the ground. All of the exposed hydraulic hoses were either left open or had rags stuffed in them. With the rains and snow, the rags were wet and contamination of the hydraulic system could not be avoided. The radiator of this truck had seen better days. The fan had eaten a large portion out of the corner, and the fix was to seal up the ends of the exposed core. Overheating of this truck was undoubtedly a part of its demise. We had asked if the management had experienced any unusual engine problems with this type of truck. They didn’t think so, but out of the 40 overburden trucks, 11 had serious engine problems. This is a problem with this model of Cat trucks. The D348 series of engine that is in this truck is infamous for its reliability problems. We have seen in other TKI mines that the maximum scheduled engine life is 5,000 hours before a rebuild, if it hasn’t failed prior to the rebuild.
The power plant was being supplied by lignite loaded from the run of mine stockpile. The responsibility of the lignite passes ownership at the top of the lignite dump hopper. The lignite truck was dumping directly into the hopper which was covered by a grizzly with openings about 0.8 meters. There was no wall or stop in which the truck could back up to. We saw evidence of a grizzly that was destroyed. The current dumping procedure is a safety hazard and can cause damage to the truck, hopper and grizzly. The lignite out of the stockpile was showing signs of spontaneous combustion and was being shipped to the power plant in a warm if not slightly smoldering state.
The maintenance repair shops are also typical of Turkish lignite operations. The floor of the shop is covered with a mixture of hard packed oil and dirt. Housekeeping is average for Turkey, but poor by US standards. A truck was having its axles and final drives worked on and oil was dumped on the floor and parts were laying about. Overhead crane capacity is adequate at 7.5 tons, but it is a limiting factor on major repairs. Unsafe practices may happen trying to lift major components. The yard outside of the shop is reinforced concrete. At this time we looked at all of the trucks in the maintenance repair yard and most of the trucks had well to excellent tread left on their tires. Good tire maintenance is evident. Preventive maintenance bays are consistent with Turkish practices with oil pits and wash down rack. Many full and empty oil barrels are in evidence. Again good housekeeping and oil spill prevention should be practiced to eliminate this environmental exposure.
The warehouse was well kept, but the inventory levels were less than other TKI mines. Some sort of inventory sharing should be established between all mines in Turkey, which have the same types of major equipment. The mine should make arrangements with Soma for the Marion shovels, and Guney Ege for the Cat 777 trucks, Bucyrus Erie 1260 dragline and the P&H 1900 shovels.
Summary
The Orhaneli Mine is a very difficult mine, but this is not unusual for Turkish Mines. The project mining costs for the TOR bid was $8.97 per ton! This appears to be an unusual low cost. Suzer and Borusan (the local Caterpillar dealer) prepared an updated cost estimate of $10.99 per ton. This estimate includes an additional $40 million of capital investment as opposed to the bid case, which had $6.5 million of additional capital investment. The cost of $10.99 per ton may be feasible, but would require extreme cost cutting measures to accomplish considering that the overall ratio is 14 to 1.
The bid did not include enough capital investment for equipment replacements, mine expansions and equipment upgrades. Suzer’s projected annual production requirements assume equal annual overburden removal for an annual production of 1.4 million tons. The annual waste removal requirements are 17 million cubic meters of truck/shovel capacity and 3.6 million cubic meters of dragline capacity. Because of the dipping seams and variability of the field, this assumption of equal annual requirements is quite optimistic. A more detailed mine planning effort will show the actual total annual waste removal requirements and project the requirement for additional production capacity and, therefore, additional capital requirements.
The following cost estimate could be used to project an average cost for the term of the project. This is based upon comparable projects in Turkey and using an average loaded and return haul cycle time of 14 minutes:
Suggestions for mine improvement:
1. Acquire the private lignite pillar in the area of Dundar Village.
2. Eliminate the dragline operations in the bottom of the pit. This will eliminate the spoil stability problems and allow the turning of the mining advance 90 degrees. The mining face will then be oriented on the dip and the advance will be in the direction of the strike. This will eliminate the dumping of the spoil on the slope above the active pit, allow a pit sump to be established in the down dip portion of the mine, and facilitate the timely establishment of backfilling operations in the area of the Gumuspinar Village.
3. Start diligent water control management practices. Establish pumps in the pit bottom to keep the pit dry and reduce the probability of spoil slide. Efforts should be made to shape and grade the backfill material in the active pit to allow the establishment of ditches and water control structures to allow the dewatering of the spoil.
4. Establish a re-powering program for the Cat 777 and Komatsu 785 trucks. Current engine lives are too short and unacceptable.
5. Establish procedures in the lignite loading operations to separate the partings and to eliminate dilution from the spoil. Turning the pits 90 degrees will facilitate in eliminating some of the spoil dilution.
6. Plan the waste dumps to facilitate the operation of the dump, reduce the wear on the trucks and create a safer working area.
7. Clean up the facilities and the shops. This would reestablish pride in the workplace and also eliminate some of the environmental concerns with spilled oils and grease.
8. Create an atmosphere of increased maintenance awareness to eliminate water and dirt contamination to increase the lives of repaired components.
9. Fix the truck dump with a small concrete wall to stop the trucks from backing into the truck dump.
10. Work with the other mines to create a pooling of spare parts to enable faster repair turnaround and to maximize the utilization of working capital.
11. Operate the mine year round to reduce cost and the stockpiling of lignite. This will also increase the quality of the lignite by reducing spontaneous combustion and dilution in the stockpiles.
We have completed the draft report of our visit to Orhaneli. Our conclusions are that at an overburden to coal ratio of over 14 to 1, this will be an expensive coal operation. Lignite costs through the term of the TOR will average over $22.00 per ton or about $2.31/mmBTU HHV.
Your comments are always welcome;
Haluk Direskeneli- Energy Analyst
ODTU ME’1973- Ankara MMO 6606
This commentary is from USAK’s Energy Review Newsletter
http://www.turkishweekly.net/energyreview/TurkishWeekly-EnergyReview9.pdf
To subscribe email to energyreview@turkishweekly.net
2012 National Coal Policy for Turkey
