Title of Invention

METHOD OF DETERMINING THE AMOUNT OF COAL MINE DUST EMISSION

Abstract

Every mine in India has to formulate an Environmental Impact Assessment (ELA) report to obtain environmental clearance from the Govt Air pollution is considered to be one of the most important parameters in an ELA report. However, there is no well-defined method for determining the amount of dust generation due to different mining activities, which ultimately increases the air pollution level. Increasing trend of opencast (OC) coal mining leads to release huge amount of dust A search into technical literature reveals that no such work has been reported in Indian context Because of site-specific nature, emission factors developed for one site may not give the correct results for another site This invention reports a noble method for the determination of dust emission due to opencast coal mining For the applications of this invention one large opencast coal project of Bharat Coking Coal Ltd. (BCCL) was investigated. The main sources of air pollution were identified. The rate of emission per unit of a given activity known as an emission factor was utilized, taking local factors into account Emission of dust due to topsoil removal, overburden (OB) removal;, extraction of coal, size reduction, wind erosion were estimated and the amount of dust emission due to all the activities are quantified. They cause air pollution in the work zone and surrounding locations. This original invention for the development of methodology for the determination of dust emission is of fundamental in nature. The significance of this invention for the protection of environment is immense and it is having wide applications in determining emission of dust due to mining activities.

Full Text

1.0 field of invention This invention relates to a method of determining the amount of coal mine dust emission due to opencast mining activities. More particularly, the invention relates to a novel method of quantifying dust generation, which ultimately increases the air pollution level in the mining areas. 2.0 Background of invention Mining operations in general have adverse environmental problems. The magnitude and significance of environmental pollution caused by mining depends on the type of mineral, method of mining and various other factors. Recent coal production survey shows mat India has been immersed as the third largest coal producing country next to China and USA in the world. India ranks among the top 10 countries in its coal resources. The existing coal resources in the country are 70 billion tonnes and accounts for 5.7% of the proved resources of coal in the world. Indian coal consumption is about 5,5% of the world. The share of coal as a source of energy in the commercial sector went up to 66%. In India coal production will have to be increased to meet the energy demand over the next 20-25 years at the rate of 20-25 Mt/y. The national plan envisages further exploitation of coal resources at a tremendously rapid rate, which subsequently will pose greater environmental problems. Underground coal mining is less detrimental to environmental degradation with respect to opencast mining. But due to various problems in underground mines some amount of technology shifted in favor of opencast mining. Indian coal production, which is in the order of 320Mt/y, is currently supporting some 7O,000MW of thermal power generation, and with developments being planned for 2010AD, this quantum of power generation is expected to increase to 150,000MW . More specifically, to meet the proposed energy needs, India must produce nearly double the quantity of coal it is mining at present, as fuel requirements will be in the range 550Mt/y By 2002 A. D., the coal production from opencast mines rose to about 80% of the total coal production. The increasing trend of opencast mining along with adaptation of large-scale mechanization lead to release huge amount of dust and gaseous pollutants. In opencast mining massive overburden (OB) will have to remove to reach the mineral deposit They may require excavator, loader, dumper conveyor belt etc., which will result in massive discharge of fine particulate from overburden materials. Similarly normal operation will require excavation, size 2 reductive waste material transportation, loading, stock piling, etc. All wiil release particulate matter. Closer ie also similar to opening for a short period. Since future plans envisages large share of opencast mining in overall coal production, it is essential to quantify the amount of dust generation to determine the impact on air environment due to the mining. But no work has been reported in this regard and a well-guided research essential. The purpose and objective of this invention was to develop a methodology to determine the amount of dust generation due to different mining activities. 3.0 Drawback associated with the known art Developmental projects go hand in hand with environmentaJ degradation. Hence before any activity is undertaken, the damages in relation to that activity should be measured. Every mine, big or small, operating or new has to obtain environmental clearance from the Govt, of India. An Environmental Management. Planning (EMP) is to be incorporated in a mining plan required to be submitted in case of afresh grant or renewals of mining leases. The Department of the Environment (DOEn) has issued guidelines for preparation of an EMP report for mining projects. Finally the Environmental Appraisal Committee (EAC) for mining projects examines the report before giving any clearance to the project. Underground coal mining is less detrimental to environmental degradation. But due to various problems in underground mines some technology has been shifted to opencast mining in India To maintain the energy demand and overall coal production, opencast coal mining has grown at a phenomenal rate The increasing trend of opencast mining along with the adaptation of large-scale mechanization leads to the release a huge quantity of dusts and gaseous pollutants. . Air pollution is considered to be one of the most important parameters in preparing an EIA report. However there is no well-defined method of determining coal mine dust generation due to different mining activities. A search into technical literature available in the subject reveals that no systematic studies have been carried out to quantify the amount of dust generation due to coal mining activities. The technology and methodology developed in other countries has its limitation in Indian condition due to difference in climatic conditions, the method of mining, geological and gemorphological setting of the area Predictions made on the impact air quality due to mining projects are not found to be correct in a number of projects in India It proves the ineffectiveness of the present system of prediction, which is not based on scientific truth and there is having drawbacks associated with the known art. 3 4.0 Object of invention Air pollution due to opencast mining is tremendous. The environmental implications of fast growing OCPs are much more in case of dust. Due to various problems some amount of technology shifts in favor of opencast mining, hi opencast mining a massive overburden will have to be removed to reach the mineraJ deposits. The main air pollution problem in a mining area is due to the presence of particulates, which may be coal, soil or rock dust Particulates find their way into the atmosphere from wind scavenged soil surface, combustion source, material transfer points, or other sources at the mine site. Strip mine air pollution source can be divided into two categories, point sources and fugitive sources. Points sources typically include stationary exhaust stacks. In contrast fugitive sources are open sources like the exposed soil of OB and coal. During dry and windy conditions, the surface soil would be scavenged by me nature of wind causing particulate matter (dust) to be suspended and transported downwind. A subset of point sources would include line sources and mobile sources of particulates. Most important is the identification and quantification of dust emission at the mine site. The object of invention relates to the attempts of developing an appropriate methodology to quantify the dust generation due to different coal mining activities. 4.1 Emission factors In coal mine planning, an estimate of dust generation is to be made to check the likely increase in the level of air pollution in the mining area due to proposed mining activities. Typically this can be obtained by using emission factors. Dust is produced at the opencast mine by drilling, blasting, overburden removal, shovel and truck loading, haul road, truck dumping, coal cleaning, conveyer transfer points, waste disposal and land reclamation. The particulate and gaseous emissions from these operations can be estimated using the technique of emission factors. The emission factor is the rate at which a pollutant is released to the atmosphere as a result of some activity multiplied by the level of that activity. Thus the rate of emission of a pollutant for a given activity is known as the emission factor and expressed as per tonne of mineral mined, per tonne of mineral crushed, per kg of explosive used etc. Because of site-specific nature of dust, emission factors derived for one site may not give the correct results for other sites. Clearly every mine was not inspected and measured. Rather individual processes were studied and emission factors had been deployed for those. An estimate was then made of the number of such processes. The total emission then equals the product of 4 emission factor times of the number of such sources. Emission factors thus represent best values for the particular processes studied. Other similar processes may not give the same emissions, In some cases very large samples were studied and in that case the emission factors may become more accurate for quantification of mine dusts. 5.0 A summary of invention Surface mining operations can result in release of particulate and gases towards atmosphere. The particulates as classified as settleable, which are greater than 100µ. in size, since they fall to earth readily under the influence of gravity. The suspended particulate matter are less than lOOµ in size, since react to Brownian molecular motion and remain suspended in the air for a long period of time. This suspended fraction is known as suspended particulate matter (SPM), which can be transported to a relatively long distance from the mine and poses air pollution problem there. The settable dust will accumulate on roadways and cause considerable damage to plants, vegetation and amenities. Generally speaking strip mine air pollution sources can be divided into point sources, area sources and line sources. Point sources typically include stationary exhaust stacks. In contrast, there are particulates that emanate from the fugitive sources, such as large open spaces. During dry and windy conditions, the surface soil will be scavenged by the action of wind, causing particulate matter to be suspended in the atmosphere and transported to down wind as fugitive particulate emissions. In opencast mining area line and mobile sources also play an important role in increasing air pollution. Tlie exhausts from trucks would be considered as a mobile source of pollutant emission. If a number of trucks pass away the same road at short intervals of time, then the source may be treated as line source. Another way also, dust generated by the truck tiers could also be considered as a mobile fugitive sources. Thus, opencast mining cannot be only considered as a point source, rather it includes multisource of emission. As it being a significant source of air pollution determination of its amount of dust emission to increase the air pollution level is very essential. But at present no such study has been reported. The methodology to be adopted for the invention is given below: 1. The main sources of air pollution in the area are to be identified like the following: -(i) Drilling and blasting (ii) Loading and unloading of coal and OB (iii) Dust due to movement of heavy vehicles along the haul road s (iv) Dragline operation (v) Crushing of coal to a convenient size in the feeder breaker (vi)Wind erosion (vii) Presence of fire (viii) Exhausts from heavy earth moving machinery. 2. Different machineries used for drilling, mining methods used, method of overburden removal, transportation system used in the mine are to be determined. 3. Different mining activities like topsoil removal, overburden removal. Coal extractions, size reduction etc. and total quantify handled per day in each case are to be measured. 4. The rate at which dust is released as a result of some activity is to be multiplied by that activity Thus the rate of emission dust per unit of a given activity is to be known as the emission factor expressed as per tonne of material mined, per tonne mineral crushed, per km of distance traveled . 5. An estimate is to be made of the number of such processes. The total emission then equals the product of emission factor times of the number of such sources. Emission thus will represent the best values for different mining activities. 6. The compilations of emission factors developed are summarized in Table 1. The emission factor datafor each activity is to be put for the quantification of dust for each activity 7. Total quantification of dust emission due all the mining activities is to be calculated adding all the dust quantified for each mining activity. 6.0 Applications 6.1 Description of the study area The Indian reserve of coking coal is mainly located in the Jharia Coalfield (JCF). Exploration started in this field in the late 19th century and rather intensely in 1925. Soon after exploration started, JCF gained its pre-eminent position because it was the main producer of prime coking coaL The coal reserves in this field accordiig to estimates by the Coal Council of India were in a seam of 0.5 m and greater in thickness and up to adepth of 610 m are 13402Mt and upto 1219 m depth are 19339 Mt. The coalfield covers an area upto 460 sq. km, and accounts formorethan 30% of the total Indian coal production, yielding about 27000 t of prime coking coal per day. The indigenous coking coal production presently does not fulfill the demand of the steel industry for which about 7 Mt of coking coal is imported annually. The extraction of coking coal is increasing at a rapid rate to meet the demand by expanding opencast coal mines. The OCT under study is one of the largest opencast coal projects for coking coal owned by Bharat Coking Coal Ltd (BCCL) in JCF. . Tlie main sources of air pollution in the area are - (i) Drilling and blasting (ii) Loading and unloading of coal and OB (iii) Dust due to movement of heavy vehicles along me haul road (iv) Dragline operation (v) Crushing of coal to a convenient size in the feeder breaker (vi) Wind erosion (vii) Presence of fire (viii) Exhausts from heavy earth moving machinery. 6.2 Determination of the amount of dust generation Opencast mining generates large quantities of dust during its various operations. Different mining activities include topsoil removal, overburden removal, coal extraction, size reduction etc. The mine was producing 2500t of Coking coal per day i.e. 0.75 Mt/yr. during the study period. The stripping ratio was 3.98 i.e. 24875 t of O/B was removed per day. Out of this, the average topsoil removal was 2400t/day. The whole OCP was divided into two parts - one box cut 3 section and one dragline section. During the study period, 60% of production of coal was from box cut 3 section and 40% from the dragline section. In the box cut 3 section, there were three O/B benches equipped with 3 power shovels (10 m3 capacity) and one coal bench with one power shovel. The average depth in this section was about 57 m. There were three-drill m/c in this section. The dragline section was equipped with one huge dragline (24 m3 ,96 m) was handling about 40% OB i.e. 8990 t/day. The dragline was equipped to remove O/B upto 35 m depth and side casted. In the box cut 3 section O/B was transported through along the haul road for about 0.5 kmi for dumping. The number of dumpers in working condition was 15. After the removal of O/B and exposure of the coal strata, coal benches were drilled, blasted and coal was transported to the feeder breaker for size reduction. The coal was crushed to -200 mm size by a feeder breaker. Coal handled by feeder breaker was about 2500 t to 3000t per day. Tlie crushed coal was transported to bunker by means of a conveyer belt from which loading to a dumper was done to dispatch to a railway siding. The feeder breaker consists of a crushing unit, transporting crushed coal by a conveyer belt, unloading into a bunker, and loading from the bunker to the dumper. 6.3 Emission factors for quantification of dust The particulate matter emissions from different mining operations can be estimated by using of emission factor data. The emission factor is a statistical average of me rale at which a pollutant is released to the atmosphere as a result of some activity multiplied by the level of activity . An emission factor may be expressed as kg of dust released per tonne of mineral mined, or per tonne of mineral crushed, or per kg of explosive used etc. For the quantification of dust generation, the emission factor data evaluated for different mining activities are given in Table 1 Opencast mining generates large quantities of dust during its various operations. Different mining activities include topsoil removal, overburden removal, coal extraction, size reduction etc. The mine was producing 2500t of Coking coal per day i.e. 0.75 Mt/y. during the study period. The stripping ratio was 3.98 i.e. 24875 t of OB was removed per day. Out of this, the average topsoil removal was 2400 t/day. The whole OCP was divided into two parts - one box cut 3 section and one dragline section. During the study period, 60% of production of coal was from box cut 3 section and 40% from the dragline section. In the box cut 3 section, mere were three OB benches equipped with 3 power shovels (10 m3 capacity) and one coal bench with one power shovel. The average depth in this section was about 57 m. There were three drill machines in this section. The dragline section was equipped with one huge dragline (24 m3; 96 m) was handling about 40% OB i.e. 8990 t/day. The dragline was equipped to remove OB up to' 35 m depth and side casted. In the box cut 3 section OB was transported through along the haul road for about 0.5 1cm for dumping. The number of dumpers in working condition was 15. After the removal of O/B and exposure of the coal strata, coal benches were drilled, blasted and coal was transported to the feeder breaker for size reduction. The coal was crushed to -200 mm size by a feeder breaker. Coal handled by feeder breaker was about 2500t to 3000t per day. The crushed coal was transported to bunker by means of a conveyer belt from which loading to a dumper was done to dispatch to a railway siding. The feeder breaker consists of a crushing unit, transporting crushed coal by a conveyer belt, unloading into a bunker, and loading from the bunker to the dumper. 9 Opencast mining activity includes topsoil removal, OB removal, coal extraction, size reduction, dispatch of coal to railway siding etc. As calculated the dust generation by the utilization of emission factor data, topsoil removal generated 69.9-kg/per day. Overburden removal operation generated 660.0 kg of dust per day; extraction of coal contributed about 256.9 kg of dust per day. Observation of dust generation due to size reduction contributed dust amounting to 6812.5 kg of dust per day. The mining activity generated dust amounting to 7799 kg of dust per day. Wind erosion also generated a huge amount of dust of about 1569.2 kg per day. Blasting also causes a huge generation of dust but due to unavailability of emission factor data the actual quantity could not be estimated. 10 Hie total amount of dust generated due to different mining activities was found to be 9368.2 kg/day (Table 2). However, the total amount of dusts generated by different mining operations is not all dispersed into the atmosphere. The larger sized particles settle down and the smallest particles become suspended in the atmosphere. Hie dust generated has its main impacts on work zone air quality with gradual dilution. But there is no direct method of correlating the predicted dust emission (computed by using emission factor data) with the suspended particulate matter (SPM), which can be measured with help of high volume air sampler. For verification of the evaluated dust emission by physical measurement is yet to be determined and more thorough research in this line is required. So, the scope of findings of this study is limited to the prediction of dust (500µ and below) emission but not for SPM (100µ- and below) 11 12 I claim 1. Method of determining the amount of dust emission due to opencast coal mixing operations comprises the steps of identifying-- the sources of dust generation, different machineries used in mining, and removal of overburden; loading and unloading of the materials, amount of materials handled, transportation systems used, distance traveled for transportation, size reduction, total quantity of such materials handled per day in each case, using emission factors used for the quantification of dust for each type of activity, determining the rate of emission of dust per unit of a given activity, per tonne of mineral mine, per tonne of mineral crushed, per km of distance traveled . 2. Method as claimed in claim 1, wherein the main sources of air pollution due to the mine are identified as follows: (i) Drilling and blasting (ii) Loading and unloading of coal and OB (iii) Dust due to movement of heavy vehicles along the haul road (iv) Dragline operation (v) Crushing of coal to aconvenient size in the feeder breaker (vi) Wind erosion (vii) Presence of fire (viii) Exhausts from heavy earth moving machinery. , 3. Method as claimed in claim 1, wherein different machineries used for drilling, mining methods used, method of overburden removal, transportation system used in the mine are identified. 4. Method as claimed in claim 1, wherein different mining activities bke topsail removal, overburden removal are determined. 5. Method as claimed in claim 1, wherein coal extractions; size reduction etc. and total quantity handled per day in each case are determined. 6. Method as claimed in claim 1, wherein the rate at which dust is released as a result of some activity is multiplied by that activity and thus the rate of emission of dust per unit of a given activity is determined and expressed as per tonne of material mined, per tonne mineral crushed, per km of distance traveled. 7. Method as claimed in claim 1, wherein determination is made based on number of such processes, the total emission then equals the product of emission factor times of the number of such sources and emission thus obtained for different mining activities. 8. Method as claimed in claim 1, wherein total quantification of dust emission due all the mining activities is determined by adding all the dust quantified for each mining activity. Every mine in India has to formulate an Environmental Impact Assessment (ELA) report to obtain environmental clearance from the Govt Air pollution is considered to be one of the most important parameters in an ELA report. However, there is no well-defined method for determining the amount of dust generation due to different mining activities, which ultimately increases the air pollution level. Increasing trend of opencast (OC) coal mining leads to release huge amount of dust A search into technical literature reveals that no such work has been reported in Indian context Because of site-specific nature, emission factors developed for one site may not give the correct results for another site This invention reports a noble method for the determination of dust emission due to opencast coal mining For the applications of this invention one large opencast coal project of Bharat Coking Coal Ltd. (BCCL) was investigated. The main sources of air pollution were identified. The rate of emission per unit of a given activity known as an emission factor was utilized, taking local factors into account Emission of dust due to topsoil removal, overburden (OB) removal;, extraction of coal, size reduction, wind erosion were estimated and the amount of dust emission due to all the activities are quantified. They cause air pollution in the work zone and surrounding locations. This original invention for the development of methodology for the determination of dust emission is of fundamental in nature. The significance of this invention for the protection of environment is immense and it is having wide applications in determining emission of dust due to mining activities.

Documents:

00076-cal-2000 abstract.pdf

00076-cal-2000 claims.pdf

00076-cal-2000 correspondence.pdf

00076-cal-2000 description(complete).pdf

00076-cal-2000 form-1.pdf

00076-cal-2000 form-18.pdf

00076-cal-2000 form-2.pdf

00076-cal-2000 form-3.pdf

00076-cal-2000 letters patent.pdf