汞在选煤边程中的迁移规律研究

基于原煤分级和全级入选不同工艺流程,测试了3个选煤厂不同洗选产品中汞含量,研究了汞在选煤过程中的迁移规律。结果显示:汞在精煤中被不同程度脱除,最小为23%,最大为76%;在中煤、矸石、煤泥中被富集,而且在矸石中的富集程度最大;降低原煤入选粒度可以增加精煤中汞的脱除率,并增加重产物中汞的富集率,因此在做燃料时要进一步研究其汞污染控制。     

酸雨对珠三角不同土壤中Pb的释放规律研究

以Pb元素为例,通过模拟酸雨,采用与自然界相接近的间歇性淋滤方式对土样进行淋滤,研究了pH酸雨对珠三角潮土和水稻土中Pb元素的溶出规律.结果表明,龙山潮土淋失量绝大多数＞0.5μg/L,pH=4.50时淋失最严重;大旺水稻土淋失量绝大多数＜0.5μg/L,最大淋失量出现在pH=2.50时的表层土,且淋失量随深度呈现减小...     

煤矸石中汞、砷的研究进展

煤矿生产过程中伴生的大量煤矸石不仅占用土地资源,而且在露天堆放的过程中其含有的有害微量元素汞、砷等会进入自然环境中,对环境造成严重污染。通过总结,介绍了国内外学者对于煤矸石中汞、砷的研究成果。主要从煤矸石中汞、砷含量,煤矸石加热汞、砷释放,煤矸石中汞、砷淋溶析出以及煤矸石中汞、砷赋存形态四个方面进行总结。以期为更多学者对于煤矸石中汞、砷的研究工作提供一定的帮助。     

岩溶山区煤矸石堆场重金属淋溶迁移特征及其对周边水体质量的影响

为探讨岩溶山区煤矸石堆场重金属淋溶迁移特征及其对周边水体质量的影响，对贵州省中部不同类型煤矸石淋溶液、地表径流、周边水体重金属进行了分析。结果显示，坡积型煤矸石淋溶液中重金属浓度明显高于残积型煤矸石，重金属浸出浓度大小顺序为Fe>Mn>Zn>Cu>Cr>Pb>Cd, Fe、Mn质量浓度范围分别是1.65～6.71,0.82～3.09 mg/L,均超出了《污水综合排放标准》(GB 3838—2019)的限值，两种类型煤矸石淋溶液中重金属浓度受降雨量影响较大；不同类型煤矸石堆场地表径流中重金属浓度差异较大，坡积型煤矸石地表径流中重金属浓度明显高于残积型煤矸石，Fe、Mn浓度在6月份最低，8月份较高，浓度变化受降雨强度的影响；岩溶地区水质受煤矸石堆场重金属迁移的影响逐渐变小，阿哈湖水库入库口水体依然有轻微的Fe、Mn污染。本研究结果为溶山区煤矿区煤矸石堆场的生态环境治理及生态修复提供了科学依据。     

煤矸石综合利用工艺探索

煤矸石是采煤和选煤过程中排放的固体废物,约占原煤的10％～20％。目前中国煤矸石综合利用率较低,为62．2％左右,造成煤矸石堆积量日益增多。大量煤矸石长期堆放不仅占用土地,而且造成环境污染,甚至威胁到矿区居民生命财产安全。结合国内外煤矸石综合利用情况,探索煤矸石的综合利用工艺。结合煤矸石减排技术、煤矸石直接利用技术、煤矸石改性利用技术、煤矸石燃烧后利用以及矸石山自燃热能利用技术,大胆提出了几种煤矸石综合利用工艺设想,希望能对国内煤矸石综合利用企业起到抛砖引玉之效。     

红柳选煤厂估算入洗原煤灰分指导配煤生产的实践

根据：原煤灰分=(精煤灰分×精煤产率+矸石灰分×矸石产率)÷100的算法原理，在上位机使用Python软件实时获取红柳选煤厂皮带秤的在线数据，计算出精煤产率、矸石产率，结合日常精煤、矸石的平均灰分(红柳选煤厂的精煤、矸石灰分比较稳定),估算出原煤灰分。然后根据精煤灰分和估算的原煤灰分，配煤生产灰分为14.50%～17.00%的产品(洗混煤),既提高了配煤产品灰分的合格率，又减少了生产过程人工采样检测灰分的劳动量。     

李家壕选煤厂提高产品发热量的措施

为提高李家壕选煤厂产品发热量,分析了原煤性质,说明原煤属低灰~中灰、低硫~中硫、特低磷、中高发热量的不黏煤和长焰煤;原生煤泥中混入较多矸石,且矸石易泥化,分选时应尽可能减少煤和矸石与水的接触时间;次生煤泥灰分极高为74.23%,矸石破碎泥化现象严重,主要集中在-0.045 mm细煤泥中。通过提高选煤厂管理水平,改造过煤溜槽,增设外来煤系统、细煤泥外排系统和矸石直接外排系统等措施对选煤厂进行改造。改造后选煤厂管理水平不断提高,原煤水分大幅降低,平均降低3%左右;外来优质煤的掺混使原煤仓、产品仓和过煤溜槽的黏堵情况得到改善,细煤泥快速回收;块精煤和混末煤产品的发热量明显提高,每年增加利润近3000万元。     

窑灰活化煤矸石水泥的性能研究

以窑灰活化煤矸石为混合材取代部分水泥熟料，测试其凝结时间、强度；以30％的取代量，研究了水泥的抗硫酸盐侵蚀和抑制碱集料反应性能。结果表明：（1）窑灰活化煤矸石的掺入使水泥凝结时向有所延长，掺入10％的窑灰活化煤矸石在一定程度上提高了水泥的后期强度，继续增加窑灰活化煤矸石的掺量，水泥的强度有所下降，掺量到30％时强度下降比较明显。（2）窑灰活化煤矸石的掺入，可使水泥的抗硫酸盐侵蚀性能有比较大的提高，抑制碱集料反应能力有所改善，但改善幅度有限。     

不同组分酸雨对水稻土镉、铜、铬的释放研究

在离子强度、pH值相同的情况下,采用一年雨量不同摩尔浓度比值的硫酸根、硝酸根模拟酸雨进行土柱淋滤的模拟试验,研究不同比值的模拟酸雨对珠三角水稻土Cd、Cu、Cr毒性元素释放的影响。研究表明:在离子强度不变的情况下,Cd、Cu、Cr在不同的SO2-4、NO-3摩尔浓度比下有不同的淋溶行为,借此可以评估硫酸型酸雨、硝酸型酸雨对农田生态系统的潜在危害,为预防与治理提供依据。     

3.2m×48m立筒预热器窑的高“三废”综合利用技术

1煤矿废矸石的化学成分原湖南省涟邵矿物局恩口煤矿年产原煤40万t,每年在掘进、开采过程中,要排出大量的煤矸石(炭质页层)、矛口灰岩、硫铁矿和长兴灰岩所组成的“废矸石”近12万t。原涟邵矿物局斗笠山煤矿年产原煤35万t,年排废矸石也达11万t。两矿10余年以来已累计堆积废矸石3     

煤灰渣酸浸提铝试验

为实现煤炭资源化分级利用,对东北某热电厂循环流化床锅炉灰渣进行提铝研究。用硫酸在不同的反应条件下酸浸,以获得较高的铝浸出率和合适的酸浸条件,产品为富含硫酸铝的酸浸液和高硅提铝残渣。酸浸实验结果表明,较为合适的酸浸条件为:5mol/L的硫酸、105～110℃的酸浸温度、2h的反应时间和1:3的固液比,此时铝浸出率为91.5%,提铝残渣中SiO₂含量高达87.6%。X射线衍射分析(XRD)和扫描电镜(SEM)分析表明,原始煤灰渣中的铝元素主要以非晶态的化合物形式存在,而非晶态物质具有较高的化学反应活性,促成了较高的铝浸出率。因此,这种循环流化床锅炉的灰渣酸浸提铝提硅较为合适。     

Preparation of SiC from acid‐leached coal gangue by carbothermal reduction

For the comprehensive utilization of coal gangue, acid‐leached coal gangue was used as silicon source and part of carbon source, low ash anthracite and degreasing cotton were added respectively as supplementary carbon source, SiC and SiC fiber were prepared by carbothermal reduction method accordingly. The results show that the main components in leached coal gangue are amorphous SiO₂ and carbon, which are suitable for the synthesis of SiC as raw materials. The synthesis temperature and holding time have important influence on the synthesis of SiC, and the optimum synthesis parameters for SiC are at 1550°C for 4 hours; under this condition, the yield of SiC is 78.27%, and the specific surface area is 6750 cm²/g. The results show that the resulting products are essentially composed of β‐SiC with a minor amount of α‐SiC. Besides, based on the carbon fiber transformation method, SiC fiber was prepared by using leached coal gangue and degreasing cotton as raw materials. Therefore, it can be concluded that leached coal gangue is a very effective and inexpensive source for preparing SiC, and more importantly, this work has important economic and social significance to realize waste recycling and control pollution.     

淮南煤矸石酸浸脱杂的研究

本文探索了一种煤矸石脱杂的新方法，考察了煤矸石粒度、焙烧温度、浸出温度、浸出剂浓度和浸出时间等条件对脱杂效果的影响。结果表明，低温焙烧盐酸浸出能有效地提高煤矸石中杂质的活性并加以脱除。     

低温中和-加压酸浸提取煤矸石中铝铁

以贵州盘县煤矸石为研究对象,为解决其工业生产提取铝铁时酸耗量大、酸利用率低及后续铝铁产品分离困难等问题,根据其矿物组成特点,本文首次采用低温中和-加压酸浸工艺对铝铁提取进行了详细研究。室温下中和最优工艺条件为20%理论酸耗、浸出时间120min、液固比3∶1（硫酸溶液与固体的质量比,以g/g计）;以中和渣为原料,煤矸石理论酸耗为基础,加压酸浸最优工艺条件为浸出时间120min、浸出温度150℃、液固比3.5∶1（硫酸溶液与固体的质量比,以g/g计）。在此条件下,氧化铁浸出率为98.37%,氧化铝浸出率为95.77%,酸浸渣灰分中氧化硅质量分数为90.2%,氧化钛质量分数为9.18%。以最优工艺条件下的酸浸液循环中和新鲜煤矸石,得到的铝铁提取液中氧化铁浓度为57.95g/L,氧化铝浓度为62.20g/L。相比常规酸浸工艺具有酸耗低、酸利用率高等优点。借助X射线衍射仪（XRD）、傅里叶红外光谱仪（FTIR）和扫描电子显微镜（SEM）等分析手段,初步对两步溶出过程进行了机理分析,为煤矸石工业生产提取铝铁提供了新路线和理论支撑。     

煤矸石中和渣酸浸物的溶出

采用浸提法提取煤矸石中和渣酸浸物中的有价元素,考察了溶出温度、溶出时间和溶出液固质量比对酸浸物溶出过程的影响;以单因素实验为基础,进行正交实验,优化溶出工艺条件,用X射线衍射(XRD)和扫描电镜(SEM)表征煤矸石中和渣酸浸物、酸化产物及滤渣的物相和微观形貌。结果表明,酸浸物溶出最优工艺条件为液固质量比3:1、溶出时间40 min、溶出温度80℃,此时有价元素氧化物的溶出率分别为TiO2 82.63%, Fe2O3 96.48%, Al2O3 98.33%, CaO 87.72%, MgO 95.31%。提取后滤渣中只有SiO2和少量TiO2及CaSO4存在,表明煤矸石中和渣酸浸物中的有价元素通过该溶出工艺可充分溶出。     

煤矸石除杂及碱融活化制取硅酸钠的实验研究

研究利用煤矸石中的硅元素制取硅酸钠,先将煤矸石粉在750 ℃下煅烧2 h,除去有机质并破坏了煤矸石中的高岭石等矿物的晶型结构,再将煅烧过的煤矸石粉在95 ℃、液固比（mL/g）为8∶1、质量分数为40%的硫酸中酸浸5 h,煤矸石煅烧粉中的铁和铝等金属杂质离子的总去除率为86.93%;还研究了碱融活化条件对硅元素溶出率的影响,获得了适宜的碱融活化条件：m（酸浸粉）∶m（碳酸钠）=1∶1.5、碱融温度为800 ℃、碱融时间为2 h。在此条件下,硅元素溶出率大于75%,最终获得了硅酸钠溶液。     

微波场中高含铁量煤矸石酸浸制备氧化铁的研究

研究了微波场中酸浸高含铁量煤矸石制取Fe2O3,探索了煅烧时间、煅烧温度、酸浸温度、酸浸时间、微波功率、HCl质量分数、煤矸石粒度对Fe2O3浸出率的影响。结果表明,在固液比1∶3条件下,煅烧时间为120 min,煅烧温度为700℃,酸浸温度为105℃,酸浸时间为30 min,微波功率为500 W,HCl质量分数为20%,煤矸石粒度为0.1753 mm,Fe2O3的浸出率可达39.36%。与传统方法相比,在大大节省时间的同时,改善了操作环境。制备的Fe2O3样品有较好的应用价值。     

由煤矸石酸浸液通氯化氢气体制备六水三氯化铝

采用向氯化铝溶液中通氯化氢气体的方法制备结晶氯化铝,考察了通氯化氢气体结晶的工艺条件,进而研究了煤矸石酸浸滤液制备六水三氯化铝过程中结晶残余液循环对煤矸石酸浸效率、杂质富集及结晶的影响。结果表明,随氯化氢气体通入量的增加及结晶温度的降低,六水三氯化铝的结晶量和结晶效率均增加。利用煤矸石酸浸滤液制备结晶氯化铝时,结晶残余液的循环利用会使酸浸液中的铝及各杂质元素富集,杂质的富集会影响六水三氯化铝结晶产品的品质,5轮循环后,结晶氯化铝的产品质量不稳定。     

Ultra clean coal production by microwave irradiation pretreatment and sequential leaching with HF followed by HNO3

The goal of this project was to develop and test an innovative coal cleaning process to reduce the ash content of coal and produce ultra clean coal (UCC). Coal samples that were prepared from concentrates of Iran's Zirab and Tabas coal preparation plants were found to have initial ash contents of 8.31 and 10.36%, respectively. These coals were demineralized with the combination of microwave irradiation pretreatment and dual acid leaching processes with HF followed by HNO₃ in a batch reactor. For samples that were microwaved and leached with HF, the reduction in ash ranged from 22 to 76% and from 22 to 82% for Zirab and Tabas coal samples, respectively, depending on leaching conditions. Microwave irradiation pretreatment had a positive effect on demineralization with HF, especially for the coarse size fractions. For the fine size fractions, reduced leaching times were found to enhance the effect of microwave irradiation. The microwave-irradiated, HF-leached product was leached further using a 1.4 M HNO₃ solution at a leaching temperature of 65 °C to remove fluoride sediments and pyritic sulfur. The ash content of the Zirab coal was reduced from 2.57 to 0.69% by leaching with the HNO₃ solution for 1 h. The ash content of the Tabas coal was reduced from 2.44 to 0.39% by leaching with the HNO₃ solution for 3 h. The results show that microwave irradiation can be considered as a pretreatment process in the chemical leaching of coal to produce UCC.     

Acid leaching of coal and coal-ashes

Twelve Turkish lignites and the corresponding ashes were leached in sulfuric acid (pH 1.0, 25 °C) for 14 days. Asphaltite from Silopi amended the coals. The conditions mimic treatment in the effluent from bioleaching of sulfidic mineral concentrates, but the results are equally valid for an isolated leaching process. The extended time meant that we approached equilibrium and maximum extraction.The coals have limited neutralizing capacity. H₂SO₄ (1.0-2.0 l, 1 M) was needed to stabilize 1 kg coal at pH 1.0 (liquid:solid ratio 10:1), but the coal-ashes required 18.0-24.0 l/kg dry solid, which is the neutralizing equivalent to CaO.Leaching of dominant inorganic phases consume acid, but our interest is merely to remove trace elements present as dopants. We removed large fractions of Mg and Mn, but Al, K and Na extractions were limited by the presence of stable minerals and bimetallic oxides. The formation of the latter is driven by combustion at high temperatures. Alumina, normally not stable at pH 1.0, was protected from the effluent by the organic phase in coal. Fe leaching varied and appeared to be a marker for different chemical occurrences in the solids.Cd, V, Zn, U and Th were leached to near 80% from the ashes, but considerably less from the coals. Co and Ni extractions were near 60%, but not always higher from the ashes compared with the coals. Cu yields increase following ashing and reached ca. 60%. Ti, Ba, and Cs were not leached.We suggest that direct acid leaching is of interest to limit the deleterious impact of ash deposits and to recirculate metals from the ash. Ash may partly replace limestone in hydrometallurgical processing, but, more importantly, metal ions extracted from ash may be fed into the metal recovery stages of such processes. It is particularly interesting to leach Co, Cu, Ni and Zn, besides Mn, V and the environmentally hazardous Cd, U and Th. Leaching of whole coals is well motivated for domestic use-lump sizes around 18-50 mm, or slightly smaller, 10 mm, if mandated by practical residence times—where generally no other measures are taken to protect the local environment.