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ASSESSMENT OF THE COAL RESOURCES OF THE KYRGYZ REPUBLIC:

COAL CHARACTER AND DISTRIBUTION, GEOLOGY, MINING, AND IMPORTANCE TO THE NATION'S FUTURE

USGS Open File Report 97-137A (English)


APPENDIX II - PRODUCTION OF SMOKELESS, WHOLE-COAL BRIQUETS IN THE KYRGYZ REPUBLIC

A. PRELIMINARY ASSESSMENT and B. AN ILLUSTRATIVE CONCEPT FOR AN ENTERPRISE

by Charles Bliss, Ch.E.

The work reported here is an update of work completed in June 1995 by the author under funding provided by the U.S. Agency for International Development through International Development and Energy Associates, Inc. (IDEA, Inc.) of Washington, DC. Much significant information upon which this report is based results from the work in Kyrgyzstan undertaken by a team from the United States Geological Survey (USGS), plus a coal mining consultant and a coal utilization consultant. This team is referred to in this report as the Assessment Team. Nevertheless, the contents of this report are solely the responsibility of the author.


A -- PRELIMINARY ASSESMENT

INTRODUCTION

Coal mining operations in the Kyrgyz Republic result in large accumulations of fine coal. From information the Assessment Team obtained in the field, this is coal of particle size less than 13 mm (0.51 inches) and perhaps, at times, less than 5 mm (0.20 inches) in size. The data indicate that the coal mine production can contain up to 70% of such unmarketable fines.

Markets in the Kyrgyz Republic for such a product are currently disappearing for various reasons, which are discussed elsewhere in the main USGS report. For example, users of coal, who depend on stoker-fired combustion, find that the fine coals either blow out through the chimney or fall through the grate into the bottom ash before they are adequately burned. Other problems with the use of fine coal occur during transport and storage. Losses of coal occur with accompanying environmental degradation. During the winter the coal fines can freeze on the conveyor belts in storage bunkers. The need for some kind of satisfactory agglomeration (lumping) technology has been recognized by researchers in the country, and their attention has been focused on conventional briquetting technology.

Compressing finely-divided coal into various shapes, suited to their ultimate uses, is a well-known technology (i.e., briquetting) with a long history. Pressure is applied to coal in a mold so that the particles adhere to each other in stable manner for subsequent handling. Some coals can adhere without the addition of a binder material, others cannot. Many different binders have been used or tested: mineral oils and tars, vegetable oils and starches, and absorbent clays such as fuller's earth and bentonite.

Any briquetting on a commercial scale must control environmental pollution and, therefore, must control obnoxious and undesirable emissions during use. Briquetting technology has advanced to the stage where acceptable control of emissions is practical, regardless of the type of use for the briquettes. In other words, the control of emissions can lie in the nature and properties of the product itself, rather than in the manner of use. Moreover, the indications are that such briquettes can be produced at a suitably low cost.

It is the purpose of this report, as an appendix to the report of the Assessment Team, to review and to bring modern developments in environmentally-acceptable, whole-coal-based briquettes to the attention of both the researchers in this field and the concerned government authorities in the Kyrgyz Republic. The briquette manufacturing technology, illustrated in part B of this appemdix, and the estimates of costs are guidance for work which must be done under the technical, economic, and commercial conditions which prevail in the Kyrgyz Republic.

PREVIOUS WORK IN THE KYRGYZ REPUBLIC

The Assessment Team, during its field work in October-November 1994, identified and reported on experimental work done by researchers in the Kyrgyz Republic in recent years. The following summarizes the findings.

In November 1994, a briquetting laboratory existed in Osh in apparently new quarters of the Institute for Integrated Use of Natural Resources (KIPR) of the Academy of Sciences of the Kyrgyz Republic. A brief visit to this facility showed that it is operational with two piston presses and mold heating capability. No information was readily available to assess the capability of this laboratory, or to know the history of its operations. In May 1996, the laboratory had just moved again, and there was no indication what space or facilities would be available for briquetting research. The new (May 1996) address of the laboratory is unknown, and telephones had not been installed. Briquetting research is headed by T. D. Dzholdosheva, but there is some indication that Sh. Kurmankulov will return to the laboratory from a teaching position, if research is resumed.

In 1995, a modified brick press (box chamber, not extrusion) was used to produce about 700 briquettes to test various binders and additives such as clays, lime powders, and cotton processing residue.

In May 1996, in Tashkent (Uzbekistan), the Assessment Team learned that I. G. Baymirov had moved from Osh to do briquetting work at the briquette factory of the Shargun mine in Uzbekistan. Present production there is with petroleum bitumen binder at a cost of about $92 per tonne, but research showed that cheaper (about U.S.$ 78 per tonne) and environmentally better briquettes could be made using cotton processing oil residues.

Published papers in Russian indicate that the goal of the earlier work had been to investigate, under laboratory conditions, the possibility of making briquettes from Kyrgyz brown coal and Kyrgyz bituminous coals with and without binders. These papers also indicate that briquettes with adequate thermal and water stability could be made using residual oils from cotton and animal fat processing in the Fergana Valley.

It has also been indicated that household briquettes could be made from brown-coal fines using bentonite clays or lime if the briquettes were treated with a waterproof coating to provide storage stability.

The Assessment Team identified four papers (in Russian), which report older work on briquetting of Kyrgyz coals. These papers are the following:

In addition, the Assessment Team reviewed an unpublished 1993 report by Zh. T. Tekenov of KIPR, Osh. This paper contains a summary of experiments, apparently mostly dealing with organic binders. References to strength, water resistance, and thermal stability probably indicate the ability of the experimental briquettes to maintain their form during handling and shipping, during storage, and during the heating process (in order to maintain the porosity of the bed). A full translation is needed, but some indication of content is the following.

In Tekenov's 1993 report, a section deals with briquetting using inorganic binders, and refers to the use of bentonitic clays and forms of lime. Bentonite clays occur in the Kyrgyz Republic in association with coal deposits. Almalyk and Sulyukta coals are associated with bentonitic clays and Kara-Kiche and Ak-Ulak coals are associated with both lime (presumably limestone) and local clays.

Comprehension of the significance of the results requires a translation of Tekenov's 1993 report and access to the reports cited above. Nonetheless, the Assessment Team concluded as follows:

CURRENT WORK ON BENTONITE-CLAY BINDER TECHNOLOGY

The potential of an absorbent clay as a binder for the manufacture of a briquette from whole (uncarbonized) coal, which would be smokeless during combustion, appears to have been first recognized in researches at Chulalongkorn University in Bangkok, Thailand, during the 1980s. The findings from this work seem to have been utilized in China. The experiences gained there have been considered by the U.S. Department of Energy in a program funded by USAID for possible application in City of Krakow, Poland, in order to mitigate the environmentally-degrading effects of the use of untreated whole coal for domestic and commercial purposes.

The Bangkok findings were also applied in Pakistan at the Fuels Research Centre (FRC) in Karachi, a unit of the Pakistan Council for Scientific and Industrial Research (PCSIR). The work began about 1987 and is continuing to the present day. The original clay used for the work was fullers earth, but later work focused on the use of bentonite because of superior results in suppressing the emissions of unburned volatile materials from the combustion of the coal. Hydrated lime was incorporated in the recipe for purposes of suppressing the emission of sulfur oxides.

Since most of the Kyrgyz coals do not have as much sulfur as the coals used in the Pakistani briquetting work, the amount of lime to be incorporated in the recipe for a Kyrgyz briquetting industry could be significantly less. However, lime could have a beneficial effect on the ultimate strength of the briquette to withstand handling and shipping. Some potassium nitrate was also incorporated in the recipe in order to promote ease in initial ignition.

The environmental performance of the Pakistani briquettes as a domestic cooking fuel to replace local fuel wood has been measured by the Oak Ridge National Laboratory of the United States Department of Energy. The basis was a comparison in a controlled environment of the emissions of the briquettes with the original coal itself, with fuel wood, with kerosene, and with dung. A perceived major market for the briquettes in Pakistan is as a substitute for scarce fuel wood. Industrial markets are also evident. The experimental work simulated the burning of the fuel under the conditions which exist in rural Pakistan. The conclusion reached was that the bentonite-based briquette would perform environmentally no worse than fuel wood under the conditions of use for cooking in rural housing.

The measurements were made by simulating the conditions during utilization in Pakistan for cooking purposes. The quantitative details and results have been reported in several instances in the literature, namely: Environment International, Vol. 19, pp 133-145, 1993, "Impact on Indoor Air Quality During Burning of Pakistani Coal Briquettes"; and a paper presented at the 6th International Conference on Indoor Air Quality, Helsinki, Finland, July 2-4, 1993, "Comparative Emissions from Pakistani Coals and Traditional Coals".

The FRC in Pakistan is equipped with a Belgian-wheel briquetting press and the ancillary facilities, which can produce briquettes round the clock at a rate of about eight tonnes per day. Currently the FRC is producing briquettes to serve a local market at a price of Rs. 1400 per tonne, which at the current exchange rate is equivalent to about U.S. $ 45 per tonne. Some interest has existed in Pakistan for the construction of a commercial plant on the scale of 50,000 tonnes per year, but such construction has not materialized as of this date for unknown reasons.

It is possible that briquettes can be produced through extrusion methods, but work on this aspect has not yet been done in Pakistan. The FRC product therefore is pillow-shaped having dimensions of about 5 cm by 5 cm by 2.5 cm thick (2-inches by 2-inches by 1-inch). These dimensions can be varied, depending on the design of the mould machined into the rotating wheels of the briquetting press.

Variations in this technology, which may have occurred in China, is a subject that needs investigation.

The basic principle of the process is the mixing of finely-pulverized whole coal with an absorbent clay such as bentonite. The mechanism which produces the smokeless properties may be theorized as follows.

If the clay during mixing coats each coal particle completely, then, as the coal particle is heated during combustion, the volatile material in the coal is emitted and absorbed by the clay which coats the particle, and retained. As the temperature in the briquette increases, the absorbed materials (primarily carbon and hydrogen compounds of high molecular weight and complex molecular structures) eventually crack, i.e., these absorbed materials break down to carbon and hydrogen compounds of low molecular weight, primarily gaseous in nature, and residual carbon. These cracked products then burn readily and smokelessly. This theory can be supported by the fact that clays are catalysts in petroleum heavy-oil cracking plants, where complex hydrocarbon molecules are broken down into simpler ones.

Sulfur dioxide emissions are controlled through incorporating hydrated lime in the recipe. Sulfur capture by the calcium-hydroxide molecules in the briquette can then reach as high as 65% overall. The bulk of the residual sulfur-dioxide emissions tends to occur at the beginning of combustion, when burning occurs at the surface and there is insufficient contact with the calcium-hydroxide molecules.

The expectation is that each coal candidate for commercial briquetting plant will have to be empirically tested in order to determine the recipe which produces the desired degree of smokelessness during use. The parameters which have to be evaluated during the formulation of such a recipe appear to be the following.

  • the particle-size distribution in the pulverized coal. If the theory described above is valid, it would appear that the surface to volume relationship of each coal particle will be a critical factor. The reason is that the volume of volatile material that would have to be absorbed by the clay coating the surface will depend on the volume of the coal particle. But the absorbing capability of the clay will depend on two factors, one of which is the amount of surface of the coal particle, the other being the thickness of the clay coating (about which see below).
    As coal particles in the mix become smaller, the volume of the particle decreases as the cube of the diameter while the surface area decreases only as the square of the diameter. The surface to volume ratios are more favorable the smaller the diameter of the particle. It would seem that the smaller the coal particle, the less excess clay may be required in the recipe.
  • the weight ratio of clay to coal in the mix. Again, based on the theory above, the amount of clay in proportion to the coal will determine the thickness of the clay coating on the coal particle, and hence the clay volume available for the absorption of the volatile material. It would appear, as already noted above, that the finer the coal particle (the greater the surface/volume ratio of the coal particle), the thinner the clay coating and the lower the clay/coal weight ratio. Thus, from a cost point of view, there appears to be a balance to be made in order to minimize the cost of the ingredients in the recipe, between the cost of the clay used in the recipe and the cost of grinding the coal.
  • the intensity (or thoroughness) of mixing the clay and the coal. It should be obvious that the intensity, or thoroughness, of mixing will determine the extent to which each coal particle is completely covered by clay. This extent is not as important in the center of the briquette, because there will be enough opportunity for absorption as the volatile material travels toward the surface. The extent will, of course, be important for the particles near the surface. In practicality, there is no practical way to control this apparent phenomenon.
  • the amount of water addition. Water is needed in order to plasticize the mix in preparation for feeding the briquetting press. This water will have to be evaporated later on, after briquetting. The evaporation of the water after briquetting should introduce porosity in the briquette, which should in turn facilitate access for the oxygen in the combustion air into the interior of the briquette. Any excess water causes heat loss; an optimum water content is indicated and this needs to be determined by trial and error.
  • the amount of lime addition. The primary function of the lime is as a sulfur dioxide absorbent. The amount of lime should be related to the amount of sulfur in the coal, and to the Ca/S molecular ratio for the desired capture. The addition of lime, however, may also have an undetermined effect on increasing the strength of the briquette in terms of downstream handling and transport. Therefore, for a low sulfur coal, the lime content may be determined more by strength considerations than by sulfur suppression needs.
  • the amount of an oxidant. An oxidant may or may not be needed, probably depending on the volatile material content in the coal. The function of the oxidant is to facilitate the initial ignition of the briquette. A commercial consideration could be the supply of two products, a starting briquette with an oxidant and a standard briquette without an oxidant. The oxidant is usually a small amount of potassium nitrate dissolved in the water used in the recipe.
  • The Fuels Research Centre in Karachi has accumulated considerable experience in recipe-formulation for a variety of Pakistani coals.

    COAL AND BRIQUETTE QUALITY

    The Assessment Team collected sixteen samples of Kyrgyz coals for laboratory analysis, one which was lost in shipment. The results of the analyses are reported in the United States Geological Survey Open-File Report titled Assessment of the Coal Resources of the Kyrgyz Republic. For convenience, the analytical results of relevance to briquette manufacture and combustion performance are reproduced here.

    The samples were analyzed for their proximate analyses, their ultimate analyses, the forms in which sulfur occurs in the coals, and their heating values. The results are reported in the tables listed below. The following box explains the headings in the tables.

        Subscripts Superscripts
    A = Ash C = Carbon ar = As received s = sulfate
    W = Moisture H = Hydrogen d = Dry p = pyritic
    VM = Volatile Matter N = Nitrogen daf= Dry, Ash-free o = organic
    FC = Fixed Carbon O = Oxygen eq = Equilibrium Moisture org = organic
    Q = Heating Value S = Sulfur   t = total
    FSI= Free Swelling Index ID= Sample Number    

    Table a-1 identifies the samples by number and the locations where they were obtained. Table a-2 reports the proximate analyses of the coal samples. Table a-3 reports the ultimate analyses of the samples and also the forms in which sulfur occurs in the samples. Table a-4 reports the heating values and the free swelling indices for the samples. Finally, Table a-5 reports the chemical composition of the ash. Table a-6 contains calculations for the expected heating values for two product briquettes, one from a lignitic (brown coal) and the other from a bituminous coal. These coals may not be necessarily identical with the coals found in the Kyrgyz Republic but which are probably sufficiently close for illustrative purposes. Thus, none of the samples identified in Table a-1 appear to be a brown coal with a moisture content of about 48%. However, sample K-10 appears to approximate closely the bituminous coal in Table a-6.

    The significance of Table a-6 is that it points out the reduction in the heating value between the initial coal and the finished briquette because of the addition of inert ingredients, the clay and the lime. Thus, it becomes important in selecting a coal for briquetting to insure that the initial ash content is low. In some cases, it may become attractive to beneficiate the coal beforehand in order to reduce ash content (and most likely sulfur content at the same time, especially the pyritic sulfur, Spd in Table a-5).

    Another observation is the high lime (CaO) content reported for samples K-1, K-4, K-7, and K-16 in Table a-5. Depending on the original chemical form of the lime in the coal mineral matter and how this content metamorphoses during combustion, the high lime content may serve as a sulfur dioxide absorber and reduce the lime requirement in the formulation of the recipe. The significance of this observation would have to be determined by experimentation.

    Finally, it should be noted that the chemical composition of the ash largely determines the ash fusion temperature. Ash fusion temperature could be important in the performance of briquettes in high combustion temperature applications, such as on the grates of stoker-fired furnaces. The criteria for predicting ash fusion and consequent slagging are complex and empirical. A discussion is, therefore, beyond the scope of this Annex.

    MARKETING CONSIDERATIONS

    The purpose of this section is to provide comments and suggestions that should be helpful in the performance of a briquette marketing assessment. This activity should be the next step after assurance exists that a recipe for briquetting exists and sample product could be made available.

    The first consideration should be the environmental acceptance of the briquettes to be offered to the market. The technical discussion above with respect to achieving a smokeless performance during combustion should make it reasonable to assume that briquettes ultimately produced from excess coal fines will have such an acceptance.

    The environmental work performed under conditions simulating domestic cooking practices in the rural areas of Pakistan, where the common source of energy is fuel wood, has already been reported above. The work employed local stoves. No attention was given to evaluating environmental performance for prospective markets in space heating, which should be of interest in the Kyrgyz Republic, or in industrial uses. However, the indications are that emissions of carcinogenous smoke and sulfur oxides should be no different.

    Two industrial uses for smokeless, whole-coal briquettes are worthy of consideration. The first is in brick making and the other can be of particular importance in improving the environmental and thermal performances of the stoker-fired furnace equipment in the Kyrgyz Republic.

    With respect to brick making kilns, the Scientific and Technological Corporation of Pakistan (STEDEC), a unit of the Pakistan Council for Scientific and Industrial Research, in 1989 undertook a market study for its briquettes in the areas of brick manufacture (a major labor-intensive industry in Pakistan), space heating for poultry farms, institutional users such as community kitchens and laundries, and domestic users.

    One useful set of findings emerged from the STEDEC work. This is shown in Table a-7. Two kilns were fired simultaneously, one with untreated coal and the other with coal briquettes. Significant improvement in the emissions, impact on the operating personnel, and reduction in fuel consumption are indicated. However, a financial analysis of the results of this brick making operation could have established a premium for the briquettes over the price of coal, but such an analysis was not reported.

    An analogous market in the Kyrgyz Republic might be the replacement in stoker-fired steam generators of the current coal by the briquettes. The findings of the Assessment Team with respect to existing practices regarding stoker-fired equipment in the Kyrgyz Republic, reported elsewhere in this document, could be useful to summarize here.

    The Assessment Team observed during its field work that the utilization efficiency of coal currently being consumed is unusually low. The basic reason is inadequate burnout of carbon from the residual ash. The Team observed residual carbon content in ash up to 40%. The expectation is that this residual content should fall usually below 1%.

    The effects of high carbon fly-ash, other than high utilization cost, are unnecessarily high costs for the district heat and electricity production, reduced effectiveness of the ash collection equipment, and greater airborne emissions with potential carcinogenic properties. Also, a high carbon content renders the ash unusable for by-product purposes. Much of this high carbon content may arise from the friable nature of the coal being burned. Fine unburned coal particles can form during the combustion process and be entrained into the gases leaving for the chimney, before the entrained coal is completely burned.

    This problem of incomplete burning of coal has been worked on locally already in Kyrgyzstan at the heat plant in Kara-Kol (Issyk-Kol Oblast). A stoker-fired boiler was modified to reduce the carbon content in the ash from 40% to 15%. The accomplishment is impressive, but further reduction in the residual carbon content is still needed. The goal should be residual carbon content less than 1%. The savings in coal consumption from bringing the carbon content of the residual ash down from either 40% or 15% could be large and worth a concerted effort.

    The effort could involve an alternative means to achieve a goal of high thermal efficiency for stoker-fired furnaces by the use of a tailored briquette as the stoker feed, instead of friable lump coal. The experience summarized in Table a-7 suggests that something similar could occur if comparable tests were made at the Kara-Kol heat plant, based on their improved operations, between the usual coal supply and a supply of smokeless whole-coal briquettes.

    The expectation may be that (1) carbon burnout could be reduced to below 1%; (2) the presence of lime in the briquette could reduce sulfur dioxide emissions materially; (3) the briquette structure could be maintained during its traverse of the stoker grate, which would, in turn, reduce the amount of fly ash to be collected; (4) less fly ash could be deposited on the tubes of the boiler, thereby increasing the heat recovery from the combustion gases and increasing the thermal efficiency of the boiler; and (5) possibly, with a hotter grate and a less opaque atmosphere in the furnace, radiant heat transfer in the furnace could increase thereby further increasing the thermal efficiency of the boiler.

    If such a test were to be run, part of the effort should be the determination of the premium on coal prices that briquettes should earn because of superior performance. The result could be compared with the cost of briquette manufacture in order to assess the profitability of such a market. In effect, if the test results support, the price which the consumer is willing to pay for briquettes over the price for coal, should be attractively less than the savings in his operating costs. At the same time, the price should be high enough to enable the manufacturer to produce briquettes at the required level of profitability.

    Briquettes for the purpose of testing the hypothesis above, could be manufactured in the facilities at Osh. It may be necessary to acquire a Belgian-wheel briquetting press with spare rolls to enable determination of the optimum physical size and shape of the briquettes, or the volume in the briquettes. The volume may have to fit the residence time of the briquette on the grate to assure carbon burnout to the level desired.

    A successful conclusion to a briquette marketing effort could lead to the prospect that much of the fine coal production from the mines would have a market through briquette manufacture.

    OBSTACLES

    Perhaps the three major obstacles to a successful introduction of a briquetting industry in the Kyrgyz Republic are (a) lack of adequate market knowledge for introducing briquettes; (b) the existence of barter; and (c) the existence of subsidies particularly on the pricing of electricity. These obstacles up to now outweigh the positive aspects that (a) a clay-based, smokeless, whole-coal briquette manufacturing technology exists and has been demonstrated and (b) available knowledge of the quality of a wide range of Kyrgyz coals indicate that suitable recipe can be found for briquette manufacture, and (c) the economic value of the fine-coal stockpiles in the Republic is zero.

    Barter discourages investment in the development, construction, operation, and maintenance of industrial facilities. Subsidy of electricity prices such that consumer prices are an order of magnitude below world prices, and laxity in the collection of bills for electricity consumption, make it impossible for an alternative fuel to compete in a free market. Meanwhile, the elimination of subsidy must be a gradual process to avoid hardship on the population.

    On the other hand, nothing needs to stop efforts to obtain a better knowledge of the potential market for briquettes in the Kyrgyz Republic.

    SUGGESTIONS

    Given the will to pursue and evaluate the potential of briquetting, it appears that the institutional means to undertake the efforts could be through expansion of the scope of the Small Enterprise Coal Mining Program. The attention of the participants in this program could be focused on the existing fine-coal stockpiles while existing government policy to support this program could be modified to accommodate the increased scope.

    In the event further investigation becomes justified and further details are desired concerning briquetting technology and capital investment and cost data, contact should be made with the author, care of Moseley, Bliss International Associates, Inc., 3133 Creswell Drive, Falls Church, VA 22044-1703, USA. Internet: cbliss1@mcimail.com


    PRODUCTION OF SMOKELESS, WHOLE-COAL BRIQUETS IN THE KYRGYZ REPUBLIC

    B -- AN ILLUSTRATIVE CONCEPT FOR AN ENTERPRISE

    INTRODUCTION

    The purpose of this addendum is to present a concept for a commercially-sized briquet manufacturing enterprise to provide guidance and relevant information which could be useful when the commercialization of briquet manufacture in the Kyrgyz Republic is considered. The expectation is that such an enterprise would be in the private sector.

    The numerical data used below are illustrative and, therefore, not indicative of prospective costs of briquet manufacture in Kyrgyzstan. Labor and equipment costs in the Kyrgyz Republic can be considerably different. The numerical data actually are illustrative of costs in the United States at a coastal location on the Gulf of Mexico.

    Nevertheless, an important and critical cost factor in the production of briquets is the cost of the presently stockpiled coal fines. The cost of this coal could range from only the costs of digging the fine coal from the stockpile and its transportation to the manufacturing plant to whatever the present owners of the coal stockpiles believe the coal should sell for.

    PRODUCTION SCALE

    The illustrative briquetting enterprise is based on an arbitrary production scale of 1,000 metric tons per day of finished briquets. This scale is selected only for the purpose of convenience. The actual scale should be selected from market and coal supply conditions.

    A block flow diagram showing the main functions for the equipment and an approximate material balance is in Figure 1. The processing shown in this figure should be self-explanatory.

    One aspect of the process, which may require specific experimental investigation, is the inherent moisture content of sub-bituminous or lignitic (brown) coals, if this moisture content is substantial. Drying the coal irreversibly to remove its inherent moisture content to acceptable levels could pose a technical problem. The need for drying may depend on meeting a heating value specification for the briquet, on reducing shipping weight, or on both. A consequence of drying is the prospect that the pyrophoric properties of sub-bituminous or brown coals may be enhanced, which can lead to hazardous spontaneous combustion of the briquets during the marketing process.

    The statements in Figure 1 concerned with lignite drying may be applicable to Kyrgyz brown coals, and the problem should be addressed with due caution. A demonstration that a brown coal briquet can be marketed successfully, without drying to remove inherent moisture, would be the simplest solution from a processing and production cost standpoint.

    Table b-8 contains a list, with descriptions, of suggested equipment, corresponding to the functions shown in Figure 1.

    CAPITAL AND OPERATING COSTS

    Table b-9 contains an estimate of the capital requirements for the construction and commissioning of a commercial facility of the 1,000 tonnes/day capacity shown in Figure 1. The cost data are 1991 U.S. cost data, if such a plant were built in a location on the Gulf of Mexico coast of the United States. It follows, then, if interest develops to pursue this technology track further, that the estimate will have to be converted to reflect the current conditions in the Kyrgyz Republic.

    Figures 2 and 3 are plant staffing diagrams, showing personnel requirements and levels of skills. The staffing is shown both for the construction period (in Figure 2) and for the operating period (in Figure 3).

    Table b-10 contains an estimate of the payroll including social benefits for the plant staffing, and the build up of the payroll during the first three years of the construction and commissioning project. The cost figures should eventually be adjusted to reflect the current conditions in Kyrgyz Republic.

    As already indicated above, the data shown in the figures and tables should be used with caution. The data are intended as a guide to planning for briquet development in the Kyrgyz Republic, rather than as inputs for industry development. It cannot be over-emphasized that local conditions in the country regarding costs and personnel should be recognized and the data in the figures and tables revised accordingly.

    CONSTRUCTION SCHEDULE

    Figure 4 is a schedule which should be possible to follow for the implementation of the construction and commissioning program, based on knowledge of the recipe for the mix to be fed to the presses, finance being available, and the construction of the plant adjacent to the stockpiles of finely-divided coal at the mine. The period of 21 months should be adjusted, depending on the supply of equipment and materials, and on the construction practices in the Kyrgyz Republic.

    ENTERPRISE ORGANIZATION

    Ideally, the expectation should be that the management philosophy of a coal mining enterprise in the Kyrgyz Republic should be one of perceiving that the products of the mining operations are two: the marketable lump coal; and marketable smokeless fuel briquets. The transfer price for the fine coal to the briquetting operations then will become an internal matter, the management being concerned primarily with the revenue stream from the sale of the lump coal and the briquets.

    Given such an integration of operations, staffing a briquetting operation should be reconsidered, since it should become practical to eliminate many positions. For example, maintenance could be combined as a single service for both the mining operations and the manufacturing operations. The same could apply to such overhead items as personnel, accounting, security, and procurement. A result would be a considerable reduction in the operating costs.

    PROBLEMS OF FIGURING ACTUAL COSTS

    Finally, no discussion can be useful at the present time with respect to calculating the total cost of production of briquets.

    As already noted, the schedule in Figure 4 would begin when the development of the recipe for the mix to be fed to the briquetting presses has been identified and found suited to the market and also acceptable environmentally.

    The staffing and staffing costs shown in Figures 2 and 3, and in Table b-10, could be subject to significant reduction through major modifications and revisions.

    One example of a possibility in respect to cost reduction lies in the value of the coal fines that currently are unmarketable. On this basis, the fine coal has a zero or negative cost. It should be expected that as soon as interest is shown in acquiring these fines, they will be perceived by present stockpile owners as a "valuable, high-cost" material.

    Knowledge of the recipe is required. Costs for the ingredients need to be established. Principles for capital recovery need to be adopted. Operating cost estimates and consequent financial analysis will have to come in due course.

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