外文翻译--酸性矿井水的预防与治理

附录A简介： 煤炭是我国的主要能源，在我国一次性能源中占76以上。煤系地层大多形成与还原环境，煤层开采后处于氧化环境，流铁矿与矿井水和空气接触后，经过一系列的氧化、水解等反应，使水呈酸性，形成酸性矿井水。对地下水以及其它环境和设施等造成一定的环境影响和破坏。本文对酸性矿井水的危害、形成原因以及对酸性矿井水的预防和治理进行了简单的阐述。关键字：采煤活动 酸性矿井水 环境影响 预防 治理1前言 煤炭是我国的主要能源，在我国一次性能源中占76以上，必定要进行大量的采煤。采煤过程中破坏了煤层所处的环境，使其原来的还原环境变成了氧化环境。煤炭中一般都含有约0.35的硫，主要以黄铁矿形式存在，约占煤含硫量的2/3。煤层开采后处于氧化环境，流铁矿与矿井水和空气接触后，经过一系列的氧化、水解等反应，生成硫酸和氢氧化铁，使水呈现酸性，即生产了酸性矿井水。PH值低于6的矿井水称酸性矿井水。酸性矿井水在我国部分煤矿特别使南方煤矿分别较为广泛。我国南方煤矿的矿井水pH值一般在2.55.8，有时达2.0。pH值低的原因与煤中含硫量高有密切关系。酸性矿井水的形成对地下水造成了严重的污染，同时还会腐蚀管道、水泵、钢轨等井下设备和混凝土井壁，也严重污染地表水和土壤，使河水中鱼虾绝代，土壤板结，农作物枯萎，影响人体健康。1 酸性矿井水的危害 矿井水的pH值低于6即具有酸性，对金属设备有一定的腐蚀性；pH值低于4即具有较强的腐蚀性，对安全生产和矿区生态环境产生严重危害。具体有以下几个方面： 1>腐蚀井下钢轨、钢丝绳等煤矿运输设备。如钢轨、钢丝绳受pH值<4的酸性矿井水侵蚀，十几天至几十天其强度会大大降低，可造成运输安全事故；2>探放pH值低的老空水，铁质控水管道和闸门在水流冲刷下腐蚀很快.3>酸性矿井水中SO42-含量很高，与水泥中某些成分相互作用生成含水硫酸盐结 晶。这些盐类在生成时体积膨胀。经测定，当SO42-生成CaSO4·2H2O时，体积增大一倍；形成MgSO4·7H2O时，体积增大430；体积增大使混凝土构筑物结构.4>酸性矿井水还是环境污染源。酸性矿井水排入河流，pH质小于4时，会使鱼类死亡；酸性矿井水排入土壤，破坏土壤的团粒结构，使土壤板结，农作物枯黄，产量降低，影响工农关系；酸性矿井水人类无法饮用，长期接触，可使人们手脚破裂，眼睛痛痒，通过食物链进入人体，影响人体健康。2 酸性矿井水形成的原因煤系地层大多形成于还原环境，含黄铁矿（FeS2）的煤层形成于强还原环境。煤炭中一般都含有约0.35的硫，主要以黄铁矿形式存在，约占煤含硫量的2/3。煤层开采后处于氧化环境，流铁矿与矿井水和空气接触后，经过一系列的氧化、水解等反应，生成硫酸和氢氧化铁，使水呈现酸性，即生产了酸性矿井水。酸性矿井水形成的主要原因即发生的主要化学反应如下：1> 黄铁矿氧化生成游离硫酸和硫酸亚铁：2FeS27O2+2H2O2H2SO4+2FeSO42> 硫酸亚铁在游离氧的作用下转化为硫酸铁：4FeSO42H2SO4O22Fe2（SO4）32H2O3> 在矿井水中，硫酸亚铁的氧化作用，有时也不一定需要硫酸：12FeS23O2+6H2O4Fe2（SO4）34Fe（OH）34> 矿井水中硫酸铁，具有进一步溶解各种硫化矿物的作用：Fe2（SO4）3MSH2O3/2 O2M SO4+2FeSO4H2SO5> 硫酸铁在弱酸性水中发生水解而产生游离硫酸：Fe2（SO4）3+6H2O2 Fe（OH）33H2SO46> 在矿井深部硫化氢含量高时，在还原条件下，富含硫酸亚铁的矿井水也可产生游离硫酸：2FeSO45H2S2 FeS23SH2SO44 H2O酸性矿井水的性质除与煤中含硫量有关外，还与矿井水涌水量、密闭状态、空气流通状况、煤层倾角、开采深度及面积、水的流动途径等地质条件和开采方法有关。矿井涌水量稳定，则水的酸性稳定；密闭差、空气流通良好，则水的酸性较强，Fe3+离子含量较多；反之，则酸性较弱，Fe2+离子较多；开采越深，煤的含硫量越高；开采面积越大，水的流经途径越长，则氧化、水解等反应进行得越充分，水的酸性越强，反之则弱。3 酸性矿井水的预防与治理3·1 酸性矿井水的预防根据酸性矿井水形成的条件和原因，可以从减源、减量、减时等三个方面进行预防或减轻其危害程度。1>减源：捡选利用造酸矿物，化害为利。煤矿床的主要造酸矿物时夹杂在煤层中的黄铁矿结核和煤本身的含硫量。煤的开采率低、残留煤柱或浮煤丢失多，黄铁矿结核废弃在井下采空区中，被积水长期浸泡，是产生酸性水的重要根源。减少工作面丢失的浮煤、积极捡选利用黄铁矿结核，能减少产生酸性水的物质。拦截地表水，减少入渗量。例如回填矸石，控制顶板，防止地面水沿塌陷裂隙浸入老空区。在井下，特别是老井或废弃封闭井巷处，对矿井水施放适量的抑菌剂，抑制或杀灭微生物的活性，或者减少矿井水中微生物的数量。通过降低微生物对硫化物的有效作用，达到控制酸性矿井水生成的目的。2>减少排水量：设立专门排水系统，集中排酸性水，并在地表拦蓄起来，使其蒸发、浓缩，而后加以处理，免除污染。3>减少排放酸性水的时间：减少矿井水在井下的停留时间，可在一定程度上降低微生物对煤中硫化物的氧化作用，从而有助于减少酸性矿井水的形成。对含黄铁矿多、硫分高、地表水渗漏条件又好的浅部煤层，或已形成强酸性水的老窖积水区，在开拓布局上要权衡利弊，统筹安排，在矿井前期不予开采或探放，留待矿井水末期处理，避免长期排放酸性水。3·2 酸性矿井水的治理在一定地质条件下，酸性水中的硫酸可与钙质岩石或其它基性矿物发生中和反应而降低酸度。用烧碱作中和剂用量少，污泥生成也少，但水的总硬度往往很高，虽降低了水的酸度，但增加了硬度，而且成本高，现已基本不用。目前，处理方法有以石灰乳为中和剂的方法、石灰石为中和剂的方法以及石灰石石灰法、微生物法和湿地处理法。石灰乳中和剂处理法适用于处理酸性较强、涌水量较小的矿井水；石灰石石灰法适用于各种酸性矿井水，尤其是当酸性矿井水中的Fe2+离子较多时适用，还可以减少石灰用量；微生物法基本原理时应用氧化铁细菌进行氧化除铁，此菌能从水生环境中摄取铁，然后以氢氧化铁形式把铁沉淀子在它们的粘液分泌物中，时酸性水的低铁转化为高铁沉淀出来，然后再用石灰石中和游离硫酸，可降低投资，减少沉渣。湿地法又称浅沼泽法，此法具有成本低、易操作、效率高等优点，具体方法在这里不再详述。结论煤系地层大多形成与还原环境，煤层开采后处于氧化环境，流铁矿与矿井水和空气接触后，经过一系列的氧化、水解等反应，使水呈酸性，形成酸性矿井水。对地下水以及其它环境和设施等造成一定的环境影响和破坏，同时会对人体健康造成一定的影响。通过对酸性矿井水的形成原因进行分析，并采取一定的预防和治理措施，可减少酸性矿井水对地下水的污染、其它环境和设施等造成的破坏以及对人体健康的影响。参考文献：1王大纯等主编，水文地质学基础，地质出版社，北京.2苑眀顺，环境及地下水水力学研究专题论文综述，长江科学院院报，1994，3.3林年丰，李昌辉，田春声等，环境水文地质学，北京，地质出版社，1990，21.附录BProfile : Coal is China's main energy in the country's total primary energy accounted for 76% and above. Most coal strata formed and restore the environment, coal mining in the oxidizing environment, Flow iron ore mine with water and exposed to the air, after a series of oxidation and hydrolysis, so that water acidic. formation of acidic mine water. On groundwater and other environmental facilities, and so on have a certain impact on the environment and destruction. In this paper, the acidic mine water hazards, and the formation of acid mine water in the prevention and treatment of simple exposition. Keywords : mining activities acidic mine water prevention and correction of the environmental impact of coal a foreword is China's main energy, China accounted for one-time energy above 76%, will conduct extensive mining. Mining process undermined the seam office environment, the reduction of its original environment into oxidizing environment. Coal generally contain about 0.3% 5% of sulfur, mainly in the form of pyrite, sulfur coal accounts for about 2 / 3. Coal mining in the oxidizing environment, flow and iron ore mine water and exposed to the air, after a series of oxidation, hydrolysis reaction to produce sulfuric acid and iron hydroxide, acidic water showed that the production of acid mine water. PH value lower than the six said acidic mine water mine water. Acid mine water in parts of the country in the South in particular coal mine were more widely. South China coal mine water in general pH 2.5 5.8, sometimes 2.0. Low pH causes and coal of high sulfur closely related. Acid mine water to the formation of ground water have caused serious pollution, while also corrosion pipes, pumps, Underground rail, and other equipment and the concrete wall, but also serious pollution of surface water and soil, river shrimp pictures, soil compaction, crops wither and affect human health. An acidic mine water hazards mine water pH is below 6 is acidic, metal equipment for a certain corrosive; pH is less than 4 has strong corrosive influence on the safety in production and the ecological environment in mining areas serious harm. Specifically, there are the following : a "corrosive underground rail, rope and other coal transport equipment. If rail, rope by the pH value "4 acidic mine water erosion, 10 days to Jishitian its intensity will be greatly reduced, Transport can cause accidents; 2 "prospecting low pH goaf water, Quality Control iron pipes and the gate under the flow erosion corrosion soon. 3 "acidic mine water SO42-content high, and cement production of certain components interact water sulfate crystallization. These salts are generated when the expansion. After determination of when SO42-generation CaSO4 2H2O, the volume increased by 100%; Formation MgSO4.7H2O, volume increased 430%; Volume increases, the structure of concrete structures. 4 "acidic mine water or environmental pollution. Acid mine water is discharged into rivers, the quality of pH less than 4:00, would fish died; Acidic mine water into the soil, damage granular soil structure, soil compaction, arid crop yields fall, affecting workers and peasants; Acid mine water humans can not drink that long-term exposure, people will limbs broken, eyes suffering, enter the body through the food chain. affect human health. 2 acidic mine water and the reasons are mostly coal strata formed in the reduction environment, containing pyrite (FeS2) formed in the seam-reduction environment. Coal generally contain about 0.3% 5% of sulfur, mainly in the form of pyrite, sulfur coal accounts for about 2 / 3. Coal mining in the oxidizing environment, flow and iron ore mine water and exposed to the air, after a series of oxidation, hydrolysis reaction to produce sulfuric acid and iron hydroxide, acidic water showed that the production of acid mine water. Acidic mine water that is the main reason for forming the main chemical reaction as follows : a "pyrite oxidation and free sulfate ferrous sulfate : 2FeS2 O2 +7 +2 +2 H2O 2H2SO4 FeSO4 2 "ferrous sulfate in the role of oxygen free Under into sulfate : 4FeSO4 +2 Cp'2Fe2 H2SO4 + O2 (SO4) 3 +2 H2O 3 "in the mine water The oxidation of ferrous sulfate, sometimes not necessarily need to sulfate : 12FeS2 O2 +6 +3 H2O 4Fe2 (SO4) 3 +4 Fe (OH) 3 4 "mine water Sulfate is further dissolved sulfide minerals in various roles : Fe2 (SO4) 3 + MS + H2O + / 2 + O2 M SO4 H2SO FeSO4 + 5 " ferric sulfate in the water occurred weak acid hydrolysis sulfate produced free : Fe2 (SO4) 3 +6 H2O two Fe (OH) 3 +3 H2SO4 6 "deep in the mine containing H2S high, the reduction of conditions, the ferrous sulfate-rich mine water can produce sulfuric acid free : 2FeSO4 +5 FeS2 H2S 2 +3 +4 S + H2O H2SO4 acidic mine water in addition to the nature and sulfur coal on the other, with the mine water discharge, confined state, ventilation conditions, seam inclination, mining depth and size, water flow channels and other geological conditions and mining methods. Mine Inflow stability, stability of acidic water; Confined poor, good air circulation, the more acidic the water, Fe3 + ion content more; Instead, the acid is weak, the more Fe2 + ion; more deep mining of coal with a sulfur content higher; The larger the area of mining, water flows through the channel longer, oxidation, hydrolysis reactions from the more full, the water more acidic strong, If not weak. 3 acidic mine water prevention and control a three acidic mine water under the Prevention of acidic mine water formation conditions and causes from source reduction, reductions, reduced when three aspects to prevent or mitigate damage. 1 "by the source : the seizure election made use of mineral acid, being the case. The main coal-bed mineral create acid when in a mixture of coal pyrite nodules and coal with a sulfur content itself. Coal mining rate is low and residual coal pillars or floating coal lost, abandoned pyrite nodules underground goaf, in which long-term water immersion, Acidic water produced is a major source. Face to reduce the loss of float coal, the use of positive seized election pyrite nodules, can reduce the production of acidic water substances. Intercept surface water, reduce infiltration. For example, the filling of waste, control of roof to prevent collapse fissures along the surface water immersion goaf. In Underground, particularly old or abandoned wells closed shaft, the mine water discharge appropriate antibacterial agent, kill or inhibit microbial activity, or reduce the microbial mine water quantity. By reducing microbial sulfide on the effective role and to control the generation of acid mine drainage purposes. 2 "reduced discharge : the establishment of specialized drainage system, centralized emission acidic water, and storing up on the surface, it evaporated, condensed, then to be addressed to remove pollution. 3 "to reduce emissions of acid water in time : to reduce the underground mine water in the length of stay, in a certain extent, to reduce the microbial coal oxidation of sulphides, thus helping to reduce acid mine water. Containing pyrite, sulfur, surface water leakage conditions for a good shallow seam, or have formed strong acidic water stagnant water in the old cellar, the pioneering layout to weigh the pros and arrangements, not early in the mine prospecting or mining, leaving the end of mine water treatment avoid long-term emissions acidic water. 2 3 acidic mine water treatment in certain geological conditions, Acidic water with calcium sulfate rock or other basic mineral occurrence and the reaction decreases acidity. Neutralizer with caustic soda used for less, less sludge is generated, but the total water hardness is often high, while reducing the acidity of the water. However, an increase in the hardness, and the high cost is no longer. Currently, treatment for a neutralizer to the milk of lime, limestone for the neutralizer and limestone - lime, microbiological method and wetlands treatment. Neutralizer milk of lime treatment method applicable to the handling of a strong acid, Inflow smaller mine water; Limestone - lime applied to various acidic mine water. especially when acidic mine water Fe2 + ions more applicable, but also can reduce the amount of lime; microbiological method applied when the basic tenets of iron oxide bacterial oxidation than iron, bacteria from the aquatic environment intake of iron, then to form ferric hydroxide precipitation-iron in their mucus secretions, Acidic water at the low iron into high-iron precipitates out and then reuse limestone and free sulfuric acid, can reduce investment, reduce sediment. Wetlands Act also known as shallow marshes, this method is low cost and easy operation, high efficiency, specific methods not go into details here. Conclusions Most coal strata formed and restore the environment, coal mining in the oxidizing environment, Flow iron ore mine with water and exposed to the air, after a series of oxidation and hydrolysis, so that water acidic. formation of acidic mine water. On groundwater and other environmental facilities, and so on have a certain impact on the environment and destruction, Meanwhile harmful to human health caused some influence. Based on the acidic mine water cause analysis, and to take certain preventive and treatment measures, reduce acid mine water pollution in the groundwater, environmental and other facilities and the damage caused to human health effects. References : 1 Wang Chun compiled, "hydrogeology basis," Geological Press, Beijing. 2 Yuan Ming-shun, the environment and groundwater hydraulics research papers on the topic, the Yangtze River Academy of Sciences reported that 1994,3. 3, Lin Feng, Li Changhui, Tian Chunsheng, "environmental hydrogeology," Beijing, geological Press, 1990,21.