Coal preparation plant assessment plan

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This post was last edited by lflsedin on 2015-5-12 at 20:44. Please provide guidance regarding the assessment scheme for coal processing plants. Coal washing is a process carried out to remove impurities from coal, improve its quality, make rational use of coal resources, and enhance the economic benefits associated with coal. It has the following distinct features. First, the processing objects are unstable. The difficulty level of coal washing processing depends on the availability of the raw coal to be washed and the requirements for the quality of the washed coal product. Generally speaking, the higher the quality requirements for refined coal, the greater the difficulty of processing it. In addition, the raw coal processed in coal washing plants comes from various mineable coal seams and different types of coal, and even some raw coal that has been artificially mixed. Due to differences in geological conditions and mining methods, the ash content of the raw coal fed into the washing process is also unstable, fluctuating from high to low. All of these increase the difficulties of coal washing production. The second is continuous multi-process production. Coal washing production features a high degree of mechanization, consisting of a continuous process flow that includes various different operational steps. There are many processes involved and the time frame for completion is short; if one step fails, it will affect production throughout the entire factory. Coal cannot be washed if the raw coal is not available, or if the machinery malfunctions; water or power outages... all of these prevent coal washing. These characteristics of coal washing production have a significant impact on the costs associated with coal washing; therefore, they must be taken into account when conducting cost forecasting, control, evaluation, and analysis. I. Prediction of coal washing costs The coal washing costs mainly consist of two parts: raw coal costs and processing fees. The cost of raw coal depends not only on the mines that supply it ensuring the quantity and quality of the coal, but also crucially on the recovery rate. The higher the recovery rate, the lower the cost of refined coal. Conversely, as the recovery rate declines, the cost of refined coal will inevitably rise. The impact of changes in coal washing recovery rate on costs can be calculated using the following formula: Impact of changes in coal washing recovery rate on costs = Actual amount of raw coal fed into the washing process × (Planned recovery rate – Actual recovery rate) × Planned conversion factor based on the output after washing × Planned unit cost. Secondly, it is the prediction of processing costs. It can be estimated based on the monthly production figures over the years and various consumption levels. Processing fees are divided into fixed costs and variable costs. Fixed costs include salaries, depreciation funds, major repair funds, and management fees. Variable costs include materials, accessories, water, electricity, etc. These costs increase as production volume rises, but not in a proportional manner; the increase is smaller than the increase in production volume. The processing cost can be estimated using the following formula: Processing cost = Fixed costs + Unit variable cost × Coal washing output. Based on the recovery rate and the estimate of processing costs, it is possible to predict the potential levels of costs and profits for that year. Assuming that the coal washing plant plans to process 10,000 tons of refined coal per year, and the recovery rate of refined coal is set at %, then the cost of raw coal per ton of refined coal is yuan, and the processing cost per ton of refined coal is yuan. Thus, the cost of refined coal is yuan per ton. The selling price per ton of refined coal is assumed to be yuan, with taxes amounting to yuan; therefore, the profit per ton of refined coal is yuan, resulting in annual profits of 10,000 yuan. II. Control and Evaluation of Coal Washing Costs Based on cost projections, the control and evaluation of coal washing costs must be carried out from two aspects: First, strengthen the management of the costs associated with the raw coal supplied to the plant. First is the management of the quantity and quality of the raw coal entering the plant. It is necessary to verify whether the quantity and quality of the raw coal brought by each coal owner to the coal washing plant match those recorded in the actual inspections and payments, and whether there are any discrepancies between the quality test results and the actual conditions. These factors are key reasons behind fluctuations in the recovery rate of the coal washing plant, increased costs, and reduced economic efficiency. Secondly, strengthen production technology management during the washing and sorting process, continuously improve operational standards, so as to maximize the recovery of refined coal. Everyone, from the plant manager to every worker, must pay close attention to the recovery rate metric. Currently, electronic belt scales can be used for measurement, allowing the amount of raw coal processed per hour and per shift to be determined. The fine coal silos and raw coal silos are inventoried at regular intervals every day; the recovery rate is calculated and made public, so that all employees in the plant are aware of it, thereby encouraging a continuous improvement in the recovery rate. Second, improve the control and assessment of processing fees. It is necessary to use the method of indicator decomposition to allocate various indicators to departments, workshops, and sections. Some indicators are under the direct control of the departments, such as costs for technical upgrades, expenses for staff professional ethics and skills training, safety awareness initiatives, and waste disposal costs. Other indicators are under the control of the workshops, such as material costs, spare parts, repair expenses, and office expenses. The workshop should have a full-time accountant to allocate workshop targets to teams or individuals. The control and assessment of indicators can be carried out using the following four methods: (1) The consumption of key materials as well as water and electricity is monitored and assessed based on physical quotas. However, given the current incomplete measurement methods, the consumption of diesel and flocculants is counted together by the production department at the end of each month, with both the supplier and the user involved in this process, in order to determine the amount consumed that month, which serves as the basis for evaluation. (2) General materials and accessories are controlled and evaluated through a quota system. A fixed monthly quota system is implemented, with the warehouse distributing supplies to various user units, which in turn allocate them to their subordinates or work teams. Material requisition forms must be filled out accurately, and at the end of the month, an account is prepared based on these consumption records, which serves as a basis for evaluating the performance of each unit, department, and workshop in terms of their consumption targets. (3) Materials for the project are issued in accordance with the budget approved by the head office, and accounting is carried out on a per-project basis. (4) Cost targets are assigned to each department; the finance department maintains separate accounts for them and provides the relevant departments (or individuals) with a \"fund usage manual.\" Savings are rewarded with points, while overspending results in point deductions (note: except for costs incurred due to some force majeure circumstances). III. How to analyze the fluctuations in coal washing costs Coal washing costs and profits are comprehensive indicators, and their changes are influenced by factors such as the output of refined coal, moisture content, ash content, efficiency, the rate at which sludge is removed from the coal, and the condition of the equipment. Therefore, analysis should be conducted from the following aspects: (1) If the coal washing plant fails to meet its production targets, the allocation of fixed costs per unit increases, resulting in lower profits; (2) If the recovery rate of the plant does not meet the planned levels, costs increase accordingly; (3) If the ash content of the refined coal does not meet quality standards, costs rise, the quality of coke decreases, revenue falls, and thus the profits from refined coal also fail to meet the planned levels ； (4) If the moisture content of the refined coal produced by the coal washing plant does not meet the quality requirements, the percentage deducted per ton increases, and the coal washing plant is responsible for covering the resulting losses; this in turn raises the costs of coal washing. (5) If the rate of coal slurry released from the plant exceeds a certain percentage, the losses incurred are even greater. If a coal washing plant has an annual production capacity of 10,000 tons of refined coal, and the refined coal recovery rate is set at %, then the amount of slime lost increases by %; the extra amount of slime lost is more than several tons, resulting in a loss of income equivalent to several ten thousand yuan. At the same time, for cases where environmental pollution is severe and exceeds the specified concentration limits by a certain multiple, a pollution discharge fee of [amount] yuan per ton of water will be imposed. Compared to the former, the sewage fee per ton of wastewater generated by coal washing plants increases by [amount] yuan. As a result, both costs and profits are affected; (6) A poor rate of equipment integrity not only impacts production but also increases repair costs, and in the event of serious mechanical or electrical accidents, the cost burden further increases; (7) If safety measures are inadequate and fatal accidents occur, this affects production as well as increasing expenses. An analysis of coal washing costs is conducted from the above aspects. The following table is formulated as a assessment scheme for evaluating coal washing plants. Detailed standards and price assessment indicators for major coking coal raw materials:
Coal type | Category | Upper limit % | Aod | G | Y | Mixed coal | Price adjustment notes | Aod% | Vod% | Sod% | G% | Y
Gas coal | I | >45 | < | >70 | ≤25 | Single coal | 1/3 coking coal | I | > | < | >70 | ≤25 | Single coal
Gas-fertilizer coal | I | > | < | >86 | >26 | Single coal | Fertilizer coal | I | > | < | >90 | >28 | Single coal
II | > | < | >85 | >26 | Can be simply mixed | III | > | < | >85 | >23 | Coal containing fertilizer >50%
Coking coal | I | > | < | >75 | <23 | Single coal | II | > | < | >75 | <23 | Can be simply mixed | III | > | < | >66 | <23 | Coal containing coking coal >50%
Lean coal | I | > | < | >45 | – | Single coal | II | > | < | >30 | – | Can be simply mixed | III | > | < | >21 | – | Mixable coal; non-coking coal <20%

Detailed standards and price assessment indicators for major coking coal refined products:
Coal type | Category | Mt% | Aod% | Vod% | Sod% | G% | Y | Mixed coal | Price adjustment notes | Mt% | Aod% | Vod% | Sod% | G% | Y
Gas coal | I | 8–10 | ≤10.5 | >28–40 | <0.8 | >70 | ≤25 | Single coal | 1/3 coking coal | I | 8–10 | ≤10.5 | >28–36 | <0.8 | >70 | ≤25 | Single coal
Gas-fertilizer coal | I | 8–10 | ≤10.5 | >37 | <0.8 | >86 | >26 | Single coal | Fertilizer coal | I | 8–10 | ≤10.5 | >22–36 | <0.8 | >90 | >28 | Single coal
II | 8–10 | ≤10.5 | >22–36 | <0.8 | >85 | >26 | Can be simply mixed | III | 8–10 | ≤10.5 | >22–35 | <0.8 | >85 | >23 | Coal containing fertilizer >50%
Coking coal | I | 8–10 | ≤10.5 | >15–30 | <0.8 | >75 | >15 | Single coal | II | 8–10 | ≤10.5 | >15–30 | <0.8 | >75 | >15 | Can be simply mixed | III | 8–10 | ≤10.5 | >15–30 | <0.8 | >70 | >15 | Coal containing coking coal >50%
Lean coal | I | 8–10 | ≤10.5 | >13–19 | <0.8 | >45 | – | Single coal | II | 8–10 | ≤10.5 | >13–19 | <0.8 | >30 | – | Can be simply mixed | III | 8–10 | ≤10.5 | >13–19 | <0.8 | >21 | – | Mixable coal; non-coking coal <20%

Assessment indicators for coal washing plants:
Coal type | Actual amount of raw coal processed T | Planned recovery rate % | Actual recovery rate % | Planned conversion factor based on post-washing output | Planned unit cost | Actual unit cost
Note: To be improved! ! ! ! ! ! ! !