Synthesis of a Goethite Pigment by Selective Precipitation of Iron from Acidic Coal Mine Drainage

Conventional treatment of acid rock drainage (ARD) from coal mines generates large volumes of sludge, which requires further treatment and disposal. The aim of this work was to study the recovery of iron by selective precipitation to synthetize goethite for use as pigment. Goethite particles were successfully produced, and presented a particle distribution in the range of nano- and micro-sizes, varying from 0.04 to 5.0 µm when produced as paste suspension, or from 0.04 to 25.0 µm when dried at 60?°C and converted to a solid powder. The pigment was used to color a white cement paste, giving it a yellow ochre color. ARD treatment plants can adopt this process to reduce waste disposal issues and produce a valuable mineral (e.g., yellow pigment for concrete).     

Ferric Sulphate Coagulant Obtained by Leaching from Coal Tailings

A ferric sulphate solution was produced from pyritic coal tailings for potential use as a coagulant for water and wastewater treatment. Laboratory-scale leaching experiments were carried out with four tailings with different concentrations of pyrite. The tailings were characterized for: total sulphur, pyritic sulphur, sulphate sulphur, organic sulphur, and elemental analysis of carbon, hydrogen, and nitrogen. X-ray diffraction analyses were also conducted to assess the mineral composition of the samples. The leaching was carried out using a laboratory column constructed as a packed bed reactor with a closed-circuit sprinkling system. After 4 weeks of leaching, the liquor was filtered and evaporated to reach an iron concentration of about 12% w/w, which is typical of most commercial FS coagulants in Brazil.     

Iron Removal by a Passive System Treating Alkaline Coal Mine Drainage

The Marchand passive treatment system was constructed in 2006 for a 6,000 L/min discharge from an abandoned underground bituminous coal mine located in western Pennsylvania, USA. The system consists of six serially connected ponds followed by a large constructed wetland. Treatment performance was monitored between December 2006 and 2007. The system inflow was alkaline with pH 6.2, 337 mg/L CaCO₃ alkalinity, 74 mg/L Fe, 1 mg/L Mn, and <1 mg/L Al. The final discharge averaged pH 7.5, 214 mg/L CaCO₃ alkalinity, and 0.8 mg/L Fe. The settling ponds removed 84% of the Fe at an average rate of 26 g Fe m⁻² day⁻¹. The constructed wetland removed residual Fe at a rate of 4 g Fe m⁻² day⁻¹. Analyses of dissolved and particulate Fe fractions indicated that Fe removal was limited in the ponds by the rate of iron oxidation and in the wetland by the rate of particulate iron settling. The treatment effectiveness of the system did not substantially degrade during cold weather or at high flows. The system cost $1.3 million (2006) or $207 (US) per L/min of average flow. Annual maintenance and sampling costs are projected at $10,000 per year. The 25-year present value cost estimate (4% discount rate) is $1.45 million or $0.018 per 1,000 L of treated flow.     

选择性沉淀法从粗硫酸镍溶液中回收铜

采用Na₂S₂O₃作沉淀剂, 从粗硫酸镍溶液中选择性回收铜, 研究了Na₂S₂O₃加入量、溶液初始酸度、反应温度以及反应时间对选择性回收铜的影响, 结果表明：在Na₂S₂O₃过量系数为3.0、溶液初始酸度0.3 mol/L、反应温度85 ℃、反应时间2 h的条件下, 铜沉淀率可达99.97%, 镍损失率仅为0.78%。     

Using Acid Mine Drainage to Recover a Coagulant from Water Treatment Residuals

We evaluated the recovery of aluminum from water treatment residuals by acidification using acidic coal mine drainage as an extraction solution. The water treatment residuals had Al and total Fe concentrations of 1.2 and 1.3%, respectively, based on mass. The influence of contact time of the mine water with the water treatment residuals and the percent of excess sulfate were assessed. The results showed that 28 min of contact and 100% of excess sulfate allowed recovery of >90% of the Al. Color was reduced from 25.9 to 0.8 total color units (TCU) and turbidity was reduced from 6 to 0 nephelometric turbidity units (NTU). The recovered coagulant performed appropriately in water treatment tests, based on physical–chemical parameters. The only parameter that requires more attention is antimony, which was close to the maximum concentration limits for drinking water.     

宝清露天煤矿疏干降水系统优化

根据宝清露天煤矿的实际情况主要分析了疏干降水的优化历程,着重阐述了明排疏干系统的方式、方法和设计方案,利用基坑降深、环沟降水、冻结法的施工方式建设水仓,成功地解决了采掘场内疏干问题,解决了松软土岩含水率高难以施工的难题。提高了设备工作效率及开拓降深速度。     

Passive Treatment of Acidic Coal Mine Drainage: The Anna S Mine Passive Treatment Complex

The Anna S coal mine complex in Tioga County, PA, produces drainage with a pH of 2.8–3.6 containing 3–36 mg/L Al, 1–36 mg/L Fe, and 6–9 mg/L Mn. In 2003, the Babb Creek Watershed Association installed two systems that passively treat three discharges from the mine complex. Both systems contain four parallel vertical flow ponds followed by aerobic wetlands. The vertical flow ponds contain a total of 35,483 t of limestone and 4,913 m³ of organic substrate. During the last 6 years, the systems have treated an average of 1,971 L/min of flow to neutral pH with 135–146 mg/L of alkalinity (as CaCO₃), with less than 1 mg/L of Al and Fe, and 2–4 mg/L of Mn. The vertical flow ponds have generated alkalinity at rates of 32–53 g/m²/day as CaCO₃. No seasonal variation in treatment effectiveness has been observed, despite relatively harsh winter seasons. The total cost of the passive systems was $2.5 million (US). The 20 year projected unit treatment cost, including periodic replacement of the organic substrate, is $2.5 million (US). The 20 year projected unit treatment cost, including periodic replacement of the organic substrate, is 403–618 per t (as CaCO₃) of net alkalinity generated.     

莱芜市垂阳铁矿主竖井排水实践

垂阳铁矿主竖井在完成井筒装备安装施工后转入平巷掘进时,出现了较大涌水而导致淹井。根据涌水特点,决定采用深井潜水泵接力排水方案排除涌水。方案实施后,取得了非常好的效果。     

本煤层抽放治理采面瓦斯技术在东海矿的应用

介绍了利用风煤钻施工钻孔,在采场动压作用下煤体产生裂隙释放瓦斯,然后利用抽排设施抽放瓦斯,治理采面局部高瓦斯区域的方法。     

北宿煤矿疏放唐村矿井积水工程系统优化

本文介绍了北宿煤矿疏放唐村煤矿老空水的工程设计及采取的措施，达到了矿井疏放和排水要求，保证了安全生产。     

陈台沟铁矿的矿井排水利用

以陈台沟铁矿的矿井排水为例,论述了矿井水在地下水源热泵方面的应用,具有节约能源和经济性双重意义。     

煤矿机械生产中石墨/铁基耐磨复合材料的应用研究

对复合材料中应用较广的石墨/铁基耐磨复合材料的性能及制作方法进行了阐述,并结合煤矿罐笼衬套对其在煤矿机械生产中的应用进行了实例分析,以期促进我国煤矿机械生产和石墨/铁基耐磨复合材料研究的进步。     

煤矿自动排水系统的应用

介绍了以可编程控制器PLC监控平台为基础的自动化控制系统,在煤矿矿井排水系统应用。首次对煤矿自动化排水系统做出了简单的介绍,阐述了该系统的组成,并对煤矿自动化排水系统做出了相关的功能分析。     

四川白鹤煤矿抽采极薄煤层瓦斯与发电利用实践

白鹤煤矿开采煤层为极薄煤层,采煤工作面隅角瓦斯经常超限,矿井建立了地面固定抽采瓦斯系统,采用顶(底)板穿层钻孔抽采工作面采空区卸压瓦斯,有效地治理了瓦斯灾害.瓦斯抽采系统运行稳定后,将瓦斯进行发电利用,实现了矿井生产和生活零电费,取得了很好的安全与经济效益.     

A Novel Method of Using Iron Nanoparticles from Coal Fly Ash or Ferric Chloride for Acid Mine Drainage Remediation

Mine Water and the Environment - Iron nanoparticles (nano Fe) were extracted from coal fly ash (CFA) or ferric chloride (FeCl3) and used for acid mine drainage (AMD) remediation. Characterisation...     

煤矿生产技术管理与煤矿安全生产的有效策略

煤炭生产环境复杂,所以煤炭生产过程中安全事故的发生概率较大,一旦发生安全事故,不仅会影响煤炭生产的连续性,同时还会对井下工作人员的生命安全带来巨大的威胁。为了有效保证井下工作人员的人身安全,同时也是保证煤炭生产的连续性,加强煤炭生产技术管理十分有必要。本文详尽介绍了煤矿生产安全策略。     

煤矿井下排水自动化系统研究

鉴于高产高效煤矿泵房排水自动化要求,研究了一种基于PLC、iFIX软件的集成系统,即煤矿井下自动化排水系统。介绍了该系统所达到的目标、系统的组成及其iFIX的相关应用。自动排水系统可以实现自动排水和地面上进行远程监控。     

煤矿瓦斯排放的安全措施

瓦斯排放是煤矿处理积聚瓦斯最常见的措施。煤矿必须认真翔实地收集瓦斯排放的具体数据,制定统一、科学的瓦斯排放措施,使矿井通风安全管理科学化、正规化。     

煤矿追排水作业的探讨

矿井排水系统在矿井生产系统中具有重要的作用,它保证了整个矿井的安全和作业人员的生命安全,排水系统的安全性得不到保障,会影响到矿井的正常生产,严重时可发生淹井事故,造成生命、财产的严重损失。十矿1309工作面突水超过矿井最大排水能力,导致矿井被淹,为了恢复生产,对矿井进行追排水作业。以十矿追排水作业进行系统性的详述,为此类作业提供有益借鉴。