【作者】 崔莉；

【导师】 程芳琴；

【作者基本信息】 山西大学 ， 环境科学， 2009， 硕士

【摘要】 煤矸石是煤炭在开采、洗选过程中排出的质地坚硬的固体废弃物,也是最多的工业固体废弃物之一。煤矸石的大量堆积给矿区带来的严重的环境污染和生态破坏;然而,煤矸石中含有二氧化硅、氧化铝、碳等化学组分,占到矸石总量的90%以上,又是一种可以利用的资源;利用煤矸石的有效成分进行煤矸石发电、生产建筑材料等成为国家支持的重点,以矸石为原料制取化工产品成为研究热点。本文以山西潞安煤矿的洗矸为原料,通过对不同煅烧温度下煤矸石的分析,确定氧化铝的活化温度区间;利用酸浸的方法对影响氧化铝溶出的主要因素进行研究,确定氧化铝溶出的最佳条件;选择适宜的添加剂,进行提高氧化铝溶出率和产品质量的研究;利用制备的聚合氯化铝絮凝剂进行高矿化度矿井水的净化研究等。实验结果表明:（1）通过扫描电镜、红外分析、x射线衍射等三种分析测试手段对煅烧前后的煤矸石进行微观形貌、化学键变化和矿物组成的分析研究,结果表明:600-850℃温度段为煤矸石的活化温度区:实验煤矸石的主要矿物组成为高岭石和石英;煤矸石具有活性的主要原因是在煅烧过程中,其中的高岭石脱水转化为偏高岭石,偏高岭石分解成γ-Al₂O₃和σ-SiO₂,γ-Al₂O₃具有溶出活性,可以被酸、碱等溶出;在活性温度区煅烧,煤矸石结构膨胀、微孔增多、比表面积增大,使煤矸石表现出良好的反应活性。（2）选取煅烧温度、酸浸时间、酸量、固液比四个影响因素设计正交实验,确定的最优工艺条件为:酸浸时间（3h）、煅烧温度（650℃）、酸量（225ml,按照煤矸石中氧化铝和盐酸反应的摩尔比为1:6计）,固液比（1:3）;粒度对煤矸石活化效率的影响实验表明:煤矸石的粒径在60-80目时,即粒径在0.2-0.3mm时,煤矸石活性最大;采用动态煅烧可以提高空气与物料接触机会,有效提高煤矸石活化效率。综合上述条件浸取煤矸石,可使氧化铝的提取率达到75%;（3）添加氧化钙、碳酸钠、氟化钠三种添加剂的实验研究表明:氧化钙和碳酸钠不能促进酸浸过程中氧化铝的提取,氟化钠对促进氧化铝的溶出具有显著的影响,当氟化钠的添加量为投加煤矸石量的2%时,氧化铝的溶出率达到90%以上;高锰酸钾氧化法除铁是一种可行的方法,除铁的最佳工艺参数为溶液pH为3.0,氧化剂（高锰酸钾）用量9 mL（浓度0.05mol/L）,料液中氯化铝质量分数30%,反应15分钟,温度（100±5）℃,在此条件下所得产品质量符合国标要求。（4）以煤矸石为原料制得的聚合氯化铝和电渗析联合法处理高矿化度的矿井水,可使其达到饮用水的水质要求。混凝试验及混凝剂性价比分析表明,聚合氯化铝的混凝效果最好,与实验其它混凝剂相比,处理成本最低。聚合氯化铝的最佳投量为4mg/L时,浊度的去除率可以达到97.71%。本研究为煤矸石高值利用提取氧化铝提供了技术支撑,开辟了煤矸石资源化利用的新途径,具有重要的意义。更多还原

【Abstract】 Coal gangue,one kind of the industrial solid wastes discharged during coal production,has become an environmental problem.It consists mainly of aluminum oxide（Al₂O₃）,silicon dioxide（SiO₂）,and carbon（C） accounting for more than 90 percent of coal gangue in weight.Coal gangue can be used as a resource for power generation and building materials production which are supported by the national government.Chemicals production from coal gangue is also the interest of researchers.In this paper,the activation temperature range of the coal gangue from Lu’an coal-mining company,Shanxi Province,was measured by analyzing the coal gangue calcined under the different temperatures.The best condition for lixiviating Al₂O₃ from coal gangue was determined according to aluminum producing rates through acid leaching.Several different additives were used in the acid leaching process to decide the impacts on the leaching rate and the Al₂O₃ quality.High salinity of mine water was treated with poly-aluminum chloride（PAC） made from the Aluminum trioxide leached from the coal gangue.（1） Microstructure changes and compositions of the gangue were measured by SEM（Scaning Electronic Microscope）,IR（Infrared Ray） and XRD（X-ray Diffraction）.The coal gangue calcined at the temperature ranging from 650℃to 850℃is highly activated.Kaolinite is transformed to metakaolin due to dehydration and metakaolin decomposed intoγ-Al₂O₃ andσ-SiO₂ in the process of calcination.γ-Al₂O₃ can be dissolved by acid and alkaline.Formation of the active component and increase in specific surface area during the calcination process are the reasons for the activation of the coal gangue. （2） Orthogonal experiments of a L₉（3³） matrix were designed with the factors of calcining temperature,acid leaching time,amount of 20% hydrochloric acid and ratio of solid to liquid.The optimum operating condition for acid lixiviating Al₂O₃ from coal gangue is that reaction time is 3 hours,calcining temperature 650℃,amount of 20%hydrochloric acid 225ml per 100 grams coal gangue,ratio of solid to liquid was 1:3.The size of the coal gangue for lixiviating Al₂O₃ is -60/+80 meshes.Leaching recovery of Al₂O₃ is more than 75%at above optimum condition.Dynamic calcination can activate gangue more efficiently.（3） Experiments of three additives,Calcium oxide（CaO）,Sodium carbonate（Na₂CO₃）,and Sodium fluoride（NaF） used in the acid leaching indicate that CaO and NaCO₃ can not promote Al₂O₃ dissolution,and NaF significantly improves the leaching rate of Al₂O₃.Leaching rate of Al₂O₃ reaches up to 90%when the amount of NaF added in the leaching is 2%of coal gangue in weight.Oxidation with potassium permanganate（KMnO₄） is a feasible method for the removal of Fe²⁺.The optimum operating conditions for removing Fe²⁺ are:9mL of KMnO₄（0.05mol/L） 30%of AlCl₃ in solution in weight,15min of reaction time,100±5℃of reaction temperature.Under those conditions the products obtained meets the national quality standard.（4）Mineralized water treated by a combined method of poly-aluminum chloride coagulation and electrodialysis can meet the quality standards of drinking water.Experiments of coagulation showed:poly-aluminum chloride is the best flocculant.The rate of removal of turbidity is 97.71%,and the dose added to the wastewater is 4mg/L.This study provides with technical support for highly efficient use of coal gangue.更多还原