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1、<p> The method of mining in China</p><p> The Known coal-bearing area is about 0.55 million km2 in China. Almost all the provices, cities, autonomous regions (including Taiwan Provice) possess certai
2、n amount of coal reserves. China is one of thc countries in the world of which the coal reserves are richest. The proved reserves accounted for 782234Mt at the end of 1985.</p><p> The main deposition chara
3、cteristics of coal formation in China are as follows:</p><p> (1) The geologic period when the coal was formed is long. From early Palaeozoic Era to the Quaternary Period coal deposition was already proved.
4、 So various types of deposting states and multiseam formation were found.</p><p> (2) The geological structures suffered by coal-bearing formations are much more, So various geological conditions are encou
5、ntered in coal depositing fields, such as folds, faults, irregular thickness and inclination of coal seams. As considering the thickness of coal seams, the amount of reserves of thin coal seams accounts for 17.36%, of me
6、diun thick coai seams for 37.84%, of thick coal seams for 44.8%; As considering the inclination of coal seams, the amount of reserves of gently inclined coa</p><p> All of the above factors determined that
7、the mining methods practically adopted must be! manifold. According of incomplete statistic information there are totally 54 of mining methods which have been experienced in China. The formation of these mining methods
8、has undergone a long period. Especially, after thefounding of P. R. China mining methods are gradually devoloping, reforming and improving, and abundant experiences have been accumulated.</p><p> China is n
9、ot only one of the countries in the world which produce large amount of coal each year, but also one of the earliest counhries in the world which exploit and utilize coal reserves.</p><p> The history of ex
10、ploiting and utilizing coal reserves in China began as early as 6 to 7 thousands years ago.</p><p> Before liberation, only the machines powered by steam engine were used in few productional link, such as i
11、n hoisting, water drainage, ventilation etc. Some quite backward mining methods, like the entry retreating mining and abandoned pillar mining etc, were employed, and the extraction and developing operations were mainly c
12、ompleted by hard handwork. The working conditions of miners and the safety conditions of coal mines ware extremely poor, there were no any measures to prevent mine hazards, a</p><p> After the founding of t
13、he P. R. China, the old mining methods were gradually reformed. In May of 1950, the resolution of "Conducting the Reform of Production Methods and safe production" was issued by the Ministry of Fuel Industry, i
14、t requires that Production reform would be carried out step by step. Firstly, the out of date mining methods would be changed into new longwall-type methods in order to raise coal recovery rate. This resolution insisted
15、the production must obey the principle of "safe</p><p> In gently inclined thin and medium thick coal seams, the old entry retreating and abandoned pillar mining method were changed into longwall mini
16、ng; In thick coal seams, high-face stoping caving method was changed into the downward inclined slicing with top-coal retained or under the protection of false timber roof, the downward horizontally slicing caving method
17、 with false top-coal or timber roof, and a few changed into ascending hydraulic filling method. Meanwhile, roof grading was carried ou</p><p> During this period, great achievement was obtained in the refo
18、rm of old mining methods. Up to 1957, the output produced by means of longwall mining in the state operated coal mines accounted for 92.6%, the coal recovery rate of mining sections raised to about 70%, and the working e
19、nvironment and conditions of safe production were apparently improved.</p><p> The roof control in longwall face eliminates the situation of no supports as in old mining methods, the support types changed g
20、radually from timber props and framed timbers to metal frictional props plus hinged bars.</p><p> in gently inclined and inclined thick or extrathick coal seams, the top-slicing caving mining under the pro
21、tection ofartificial false roof was tested and improved. The oringinal false timber roof was changed into bamboo curfain, waaved twigs of the chaste tree, and mainly into metal-mesh false roof. Moreover, clay grouting w
22、as used for forming regenerated roof. In gently inclined extrathick coal seams, ascending inclined slicing longwall mining on the strike associated With hydraulic filling w</p><p> For steeply inclined thin
23、 and medium thick coal seams, inverted bench mining by means of compressed air hammer was tested at the beginning, then tongwall mining was adopted. In steeply inclined thick coal seams, the horizontally slicing and slan
24、t slicing were practised firstly, and the method of mining under the protection of flexible shields was latter tested successfully and spreaded. Besides, the strip shrinkage stoping to the rise, the oblique longwall-type
25、 shrinkage stoping on the strike an</p><p> Many experiences have been accumulated in the process of adopting longwall mining. For example, the clay grouting used in inclined slicing longwall caving mining
26、on the strike for extracting thick and extrathick coal seams can not only prevent spontaneous combustion of coal, but also be advendtageous to forming regenerated roof, thus improve roof conditions and enhance the applic
27、ation scope of downward caving mining method. Another example is changing the double-entry system into single-entry sy</p><p> At the mean time, developing mechanized mining to ease the hard labour works wa
28、s paid much attention by the government. The MLQ-64 type shallow-web single drum shearer, which was made out in Xiaohengshan Coal Mine (Jixi CMA), combined with SGW-44 type chain scraper conveyor, metal frictional props
29、 and hinged bars equipped the first ordinary mechanized working face in 1964, which realized the mechanization of coal extraction, loading and conveying operations. Such an ordinary mechanized mining m</p><p&g
30、t; In order to further improve the longwall mining, researches on fully mechanized mining were carried out. The first set of fully mechanized mining equipment, which was designed and made domestically, was tested underg
31、round in 1974. Meanwhile, complete sets of fully mech anized mining equipment were imported from abroad.</p><p> In 1978, fully mechanized mining entered a new developing period in China after the Third Me
32、eting of Eleventh central Commitee of the Chinese Communist Party. In September of 1979, the first "Technical Policies of Coal Industry" was issued by the Ministry of Coal Industry, it stipulated that fully me
33、chanized mining is the developing direction of coal industry.With reforming and opening, more than 100 sets of fully mechanized mining equipment were imported and wide-ranging international exchange</p><p>
34、 To suit the development of coal industry, the new "Technical Policies of Coal Industry" was revised and issued in 1987, which further indicated that the development of fully mechanized mining must be speeded.&
35、lt;/p><p> The developing history of fully mechanized mining is introduced in Table 1-1.</p><p> Latter, the newly manufactured MLQ2-80 type, DY-100 type and DY-150 type single drum shearer, MLS3
36、p-170 type double-drum shearer replaced the MLQ-64 type, MLQ2-80 type single drum shearer, the new SGW-150 type chain scraper conveyor replaced the SGW-80 type conveyor, the individual hyeraulic props replaced the metal
37、frictional props. Above mentioned 3 kinds of new face equipment formed the second generation of ordinary mechanized mining, which was tested firstly in Feicheng CMA and achieved good</p><p> At the same per
38、iod, the blasting mining technology of longwall faces developed quickly.several new techniques, such as the blasting with millisecond delay detonator, the blasting-proof type individual hydraulic props the double-speed l
39、arge, power chain scraper conveyor and the technology of loading coal with the help of blasting et., have been successfully tested and spreaded gradually in suitable conditions.</p><p> Moreover, the hydrau
40、lic supports used for the fully mechanized mining with top-coal drawing and the corresponding mining technology have been studied and tested since 1982. The first set of equipment for fully mechanized mining with top-coa
41、l drawing was tested in the gently inclined extrathick coal seam of Puhe Coal Mine (Shenyang CMA) in June of 1984. In April of 198'6 this mining method tested again in the steeply inclined extrathick coal seam of No.
42、2 Coal Mine (Yiaojie CMA) and achieved good </p><p> The method of fully mechanized mining with top-coal drawing was also tested in the gently inclined thick and extrathick coal seams in Pingdingshan CMA, Y
43、angquan CMA, Luan CMA etc. some of them achieved good results. But some problems have not been resolved yet, such as the spontaneous combustion of coal, the accumutation of dust and methane, the unstable coal recovery r
44、ate etc.</p><p> The method of top-coal drawing mining with the help of sliding-bar type supports was tested in some steeply inclined and gently inclined extrathick coal seams. For example, in Huating Coal
45、Mine (Ganshu Province), Baizhigou Coal Mine (Bing County of Shanxi Provice) and Xinyao Coal Mine (Chongxin County of Ganshu Province) the technico-eco-nomic indices of this mining technology are apparently better than t
46、hat of the old mining methods. However, some problems still exist, they are mainly that the</p><p> It has been clearly regulated in the "Technical Policies of Coal Industry" that fully mech- aniz
47、ed mining is the developing direction in our country. After undergoing researches, tests and application, a series of fully mechanized mining equipment suitable to extracting gently inclined working faces with medium min
48、ing height have been formed preliminarily, which have had the capacity of satisfying the domestic needs. The developing directions of fully mechanized mining in next step are:</p><p> actively raising the o
49、perating ratio of the equipment and the working-time utilization rate; increasing the monthly face production and economic profit;improving the current equipment, increasing its capacity and reliability;focusing eff
50、orts on developing the fully mechanized mining equipment used for difficult conditions, such as the "weak-3', "hard-3' (here the number 3 means the roof, the coal seam and the floor), big inclination a
51、ngle; large mining height etc;</p><p> It is considered that the fully mechanized mining technique used in simple gently inclined medium thick coal seams or the thick coal seams mined by slicing has been ri
52、pe. Generally speaking, this technique has been reached or approached to the internation level of early 80’s, and has achieved significant technico-economic results. The fully mechanized mining technique used in gently
53、inclined thin coal seams (the hardness being of less than mediam grade, the thickness of more than 1.1 m), inclin</p><p> When equipping fully mechanized faces, it is prior to be considered for better condi
54、tions, such as stable roof conditions, gently inclined (less than 15。) medium thick and thick coal seams mined by means of multislicing, fully-seam mining (with a thickness of 3.5~ 4.0m)etc. Then some particular conditio
55、ns would be considered, such as the fullY-Seam mining (with a thickness of 4.0 ~4.5m and an inclination angle of less than 15º), the medium thick coal seam with a hard-caving roof, and the thin co</p><p&g
56、t; In addition, the high-output and high-efficiency fully mechanized mining equipment would be studied and manufactured for suitable coal seam conditions in our country, in order to greatly increase the monthly face out
57、put and keep pace with the advanced level of the world.</p><p> Now,ordinary mechanized mining still accounts for a certain proportion in China. According to the geological and technico-economic conditions
58、 of out country, ordinary mechanized mining still has broad developing prospects in the future. Moreover, new type reliable equipment of large power and high efficiency would be studied and manufactrued for ordinary me
59、chanized mining, in order to further raise the equipment level in ordinary mechanized ,working faces.</p><p> Since the end of 1970's pillarless mining developed quickly, the technique of driving en tri
60、es or retaining entries along gob edges got much development. Especially, the sidewall ill. ling technique for the entries retained along gob edges achieved success, which opened a broad prospects for pillarless mining a
61、nd created more favourable conditions for enlarging the appli. cation scope of advancing mining. In addition, the success of mining over raises or crosscuts improved the maintenance of ent</p><p> Combined
62、sectional layouts will be employed in a long period because multiseam-depos. iting formations are encountered in most cases in China. However, it needs developing to the direction of simplification, centralization and pi
63、llarless mining. Cheaper sidewall filling mate rials and sidewall filling technologies also need to be further studied. Under suitable conditions, centralized layout in each seam, retaining entries along gob edges and ad
64、vancing mining are adopted.</p><p> Sets of continuous miners were imported form U.S.A, and room & pillar mining with continuous miners was tested in Jixi, Datong, Xishan CMA and some local government o
65、perated coal mines. This method has achieved certain results under suitable geologic conditions but it was strictly confined by geologic conditions.</p><p> Hydro-mechanical mining began in 1950's in Ch
66、ina. the cutting pressure increased fron 5~' 6MPa to 12-- 14MPa in 1960's. The 20 MPa high-pressure hidro-mechanical mining technique was carried out in 1970’s. Now the cutting pressure practically used is genera
67、ll,above 10MPa, only in few weak coal seams cutting pressure of less than 10MPa wa employed. Shortwall unsupported hydero-mechanicalrnining is the main from of nowadays hydro-mechanical mining technology, this method was
68、 used for extracting th</p><p> The advantages of hydro-mechanical mining are: simple equipment, high degree of mechanization, continuous operation, single mining operation, easily mastered techniques, easi
69、ly realized fully automatic control of the production system etc. Hydraulic mining can be applicated for the following conditions: </p><p> (1) The roof is stable or medium stable, the methane content is
70、 low, the coal hardness is of medium grade or softer, no hard and thick partings exist in the coal seam, the thickness of seam is 3--8m and the seam is steeply inclined.</p><p> (2) The roof is stable or me
71、dium stable, the inclination angle is larger than 10 。, the geological structure is complex, the strike and thickness of the coal seam vary greatly, and the seam is irregularly dleposited.</p><p> (3) The
72、seam needs remined.</p><p> Mining under water bodies began in 195frs in China. At the beginning the thick coal seams and multiseams were tried to be extracted under water-bearing alluvium. In 1970's, t
73、he coal reserves under Huai River, Zi River, several large reservoirs, water bearing base rocks; and aquiferous karsts were well extracted. Mining under buildings began in 1960’s. The sur- face and underground protecting
74、 measures for mining under buildings have been competely studied and systematic experiences have been summ</p><p> As mentioned previously, because of the import and research of fully mechanized mining equi
75、pment as well as the development of fully mechanized mining the longwall mining method is gradually perfected. In addition, the ordinary mechanized mining, the blasing longwall mining, the mining in some special conditi
76、ons (for example the mining under “3-bodies”) and hydro-mechanical mining method are also existing manifold mining methods taking the longwall mining as the dominant method is gradually for</p><p> our coun
77、try.</p><p> The development of surface mining can be divided into 3 periods. The first is the "First 5-Year Plan" period when the Haizhou, Fushun, Xinqiu surface coal mines were newly constructed
78、 or enlarged. The 3~ 4m3 shovels and 150t electric locomotives driving on the railroad with standard gauge or steams engine locomotives were used, and some equipment was imported from abroad. 196frs is the second deve
79、loping period when a group of surface mines equipped mainly with home-made equipment were constru</p><p> The proportion of the production produced by surface coal mines are very low, it accounts only 3~ 5
80、% .of the total coal production of the country now. Studying high-efficiency technology and equipment is the bases of developing surface mining. Beside of improving the current mining technology (the shovel-truck and sho
81、vel-truck and shovel-railroad mining technology), new technologies suitable to the geologic and economic conditions of the surface coal mines in our country would be developed, suc</p><p><b> 中國采煤方法&l
82、t;/b></p><p> 我國煤炭資源豐富,已知含煤區(qū)域面積約55萬多km2,絕大多數(shù)省、市、自治區(qū)(含臺灣省)都賦存有不同數(shù)量的煤炭資源。根據(jù)1985年末全國累計探明總們量為782234Mt。</p><p> 我國煤炭資源賦存有以下主要特點,一是煤炭形成的地質(zhì)年代長,從早古生代至第四紀,均有煤炭沉積。具有工業(yè)價值的煤層形成始于早石炭世,成煤期自老而新有早古生代、早石炭世、
83、早二迭世、石炭二疊紀、晚二疊世、晚三疊世、早侏羅世、中侏羅世、白堊紀、第三紀及第四紀等11個地質(zhì)年代。早古生代是石煤的主要形成時期,第四紀僅有泥炭堆積。其余9個成煤期中,石炭二疊紀、早中侏羅紀及晚侏羅紀和第三紀,是我國三大聚煤期。因此,形成多類型,多煤層的賦存狀態(tài);二是地質(zhì)構造多,煤層賦存條件多樣,1988年統(tǒng)配煤礦可采儲量中,按煤層厚度分,薄煤層占17.36%,中厚煤層占37.84%,厚煤層占44.80%;按煤層傾角分,緩傾斜煤層占8
84、5.95%,傾斜煤層占10。16%,急傾斜煤層占3.89%。</p><p> 我國是發(fā)展中國家,幅員遼闊,人口多,底子薄,各地區(qū)技術、經(jīng)濟發(fā)展不平衡,結(jié)合資源特點,應用了多種采煤方法,據(jù)不完全統(tǒng)計,我國現(xiàn)采用的采煤方法達50余種,是世界上采煤方法最多的國家之一。這些采煤方法的形成,經(jīng)歷了漫長的歲月,特別是新中國成立后,經(jīng)過改革、發(fā)展、完善,積累了豐富的經(jīng)驗,形成了具有我國特點的采煤方法體系。</p>
85、;<p> 我國不僅是當今世界上煤炭產(chǎn)量最多的國家,也是世界上最早開發(fā)利用煤炭的國家,早在六、七千年以前就已開始開發(fā)利用煤炭,有著開采煤炭的悠久歷史。 ·</p><p> 1840年鴉片戰(zhàn)爭之后,淪為半封建半殖民地的我國煤礦,采煤方法落后,采用原始的穿峒式、殘柱式、高落式等采煤方法,采掘等主要作業(yè)依靠工人繁重的體力勞動。</p><p> 1895年以
86、后,日、英、德帝國主義相繼在我國開礦,20世紀30年代, 日本帝國主義占領了我國東北,把掠奪中國煤炭資源作為其窮兵黷武的重要資源,采煤方法更向著富有掠奪性的方向發(fā)展,濫采亂挖,開采的煤炭資源損失率高達70~80%以上;礦工的勞動條件極端惡劣,煤礦的安全狀況極差,傷亡事故嚴重。</p><p> 1945年抗日戰(zhàn)爭勝利后,大部分煤礦為國民黨政權接管,采煤方法基本沒有改變。</p><p>
87、; 1.對舊中國采煤方法的改造(1949—1957年)</p><p> 新中國成立后,即對舊中國的采煤方法進行改革。1950年5月,燃料工業(yè)部在全國煤礦會議上作出了國營煤礦推行生產(chǎn)方法改革和安全生產(chǎn)的決議,提出要有計劃、有步驟地進行生產(chǎn)改革。首先從改革采煤方法開始,把落后的穿峒式、高落式、殘柱式等舊采煤方法,改為新的長壁式采煤方法,以提高煤炭資源回收率,保護國家資源。強調(diào)在安全的原則下進行生產(chǎn),改善礦井通風
88、,改善工人的勞動環(huán)境和安全生產(chǎn)條件,通過了《關于全國煤礦全面推行新的采煤方法的決定》,強調(diào)指出“采煤方法的改革是煤炭工業(yè)的一次革命”。</p><p> 在緩傾斜薄及中厚煤層中,將殘柱式和穿峒式改為單一長壁工作面采煤方法;在緩傾斜、傾斜厚煤層中,將高落式等采煤方法改為傾斜分層下行垮落采煤法,少數(shù)特厚煤層改用走向長壁上行水砂充填采煤方法,對急傾斜厚煤層則改用了水平分層下行垮落采煤法。到1957年,國營煤礦以長壁式
89、為主的新采煤方法的產(chǎn)量比重達到了92.6%,采區(qū)回采率提高到70%左右,工人的勞動環(huán)境和安全生產(chǎn)條件得到了明顯改善。</p><p> 2.長壁式采煤方法的鞏固與發(fā)展(1957~1974年)</p><p> 我國長壁式采煤方法的鞏固與發(fā)展,是在不斷改善頂板管理和提高采煤機械化程度的過程中實現(xiàn)的。在頂板管理方面,改變了舊采煤方法無支護的狀況,采煤工作面從采用各種形式的木支架到推廣應用金
90、屬摩擦支柱和鉸接頂梁。</p><p> 在緩傾斜、傾斜厚及特厚煤層,主要是推行和完善傾斜分層下行垮落采煤法,改進人工假頂?shù)匿佋O,采用竹笆假頂、荊條假頂、金屬網(wǎng)假頂?shù)纫源婺景寮夙?,發(fā)展了以金屬網(wǎng)為主要假頂材料的鋪網(wǎng)工藝;并推行黃泥灌漿等措施以形成穩(wěn)定的頂板;同時,在緩傾斜特厚煤層中,推行了傾斜分層上行水砂充填采喋方法。</p><p> 為在厚和特厚煤層中安全可靠地應用傾斜分層走向長
91、壁下行垮落采煤方法,采用了黃泥灌漿,不僅起到了預防煤層自然發(fā)火的作用,而且有利于形成再生頂板,使頂板狀況得到改善,擴大了下行垮落采煤方法的使用范圍。 </p><p> 對急傾斜薄及中厚煤層開采,先后推廣應用了風鎬落煤的倒臺階采煤法及爆破落煤的單一長壁采煤法。對急傾斜厚煤層,主要推行水平分層和斜切分層采煤法,并在試用掩護支架采煤方法的基礎上,創(chuàng)新了偽斜柔性掩護支架采煤法,大大豐富了急傾斜采煤方法的內(nèi)容。與此同
92、時,對工作面無支護的急傾斜煤層采煤方法,如仰斜條帶式倉儲采煤方法、偽斜走向長壁倉儲式采煤方法、小階段爆破采煤方法、巷道長壁采煤法及鋼繩鋸采煤法等,都進行了試驗和應用,取得了一定效果。</p><p> 在推行長壁式采煤方法的過程中,我國十分重視發(fā)展機械化采煤,以進一步減輕工人的繁重體力勞動。從50年代開始,在雙鴨山,雞西、淄博、大同、淮南等礦區(qū)使用過深截深框式采煤機。1964年研制成功MLQ-64型淺截深單滾筒
93、采煤機,與SGW-44型可彎曲刮板輸送機配套,采用金屬摩擦支柱和金屬鉸接頂梁,形成了當時的普通機械化采煤工作面。使采煤工作面的落煤、裝煤、運煤和移置輸送機等工序?qū)崿F(xiàn)了機械化。這種普通機械化采煤較快地得到了推廣,采煤機械化程度,由“一五”(1953—1957年)期末的4.11%提高到“三五”(1966—1970年)期末的15.3%,使長壁式采煤方法得到了鞏固和發(fā)展。</p><p> 3.長壁式采煤方法多種采煤工
94、藝的發(fā)展及采煤方法的現(xiàn)狀(1974—1990年)</p><p> 為了進一步發(fā)展長壁式采煤方法,我國參照國外發(fā)展采煤機械化的經(jīng)驗,進行了綜合機械化采煤設備的研制與試驗,1974年第一批自行設計、制造的綜采設備,在井下進行試驗。與此同時;成套引進了國外的綜采設備,消化、吸收國外的經(jīng)驗,以便更快、更好地發(fā)展我國的綜合機械化采煤。</p><p> 1978年,中國共產(chǎn)黨十一屆三中全會以后
95、,我國國民經(jīng)濟進入了一個新的發(fā)展時期。1979年年初,原煤炭工業(yè)部召集了有關專家,系統(tǒng)研究和制訂了我國第一個較全面的《煤炭工業(yè)技術政策》,并于同年 9月頒發(fā)執(zhí)行,明確了綜合機械化采煤的方向。</p><p> 隨著改革、開放,先后從國外引進了100多套綜采設備,并和國外進行了廣泛的技術交流,加速了我國綜采設備的攻關和研制工作,現(xiàn)在我國已經(jīng)能夠自行設計、制造緩傾斜薄及中厚煤層和厚煤層傾斜分層工作面的綜采設備以及緩
96、傾斜厚煤層的綜采設備,在主要技術性能方面,接近國外80年代先進水平。從而使我國的綜合機械化采煤有了較大的發(fā)展,并推動了采煤方法的進一步完善。</p><p> 為了適應煤炭工業(yè)發(fā)展的需要,1987年又修訂和頒布了新的《煤炭工業(yè)技術政策》,進一步指出要加快發(fā)展綜合機械化采煤。歷年來綜合機械化采煤發(fā)展情況如表1—1所示。</p><p> 在發(fā)展綜采的同時, 注意提高普通機械化采煤設備的
97、能力和可靠性,1978年后先后研制了 DY-100、DY-150型單滾筒采煤機、MLS3p-170雙滾筒采煤機以替代MLQ-64、MLQ2-80型單滾筒采煤機;以SGW-150、SGB-150C型刮板輸送機替代SGW-40、SGW-44、SGW-80型刮板輸送機。特別是研制成功了單體液壓支柱代替金屬摩擦支柱。用這三者配套形成新的第二代普通機械化采煤設備;在肥城礦務局進行了試驗,取得了良好的技術經(jīng)濟效果,把普通機械化采煤向前推進了一大步。
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