Barium Carbonate Process for Sulphate and Metal Removal from Mine Water

Abstract.  The removal of sulphate and metals from mine water was assessed using the integrated barium carbonate process and the co-precipitation of barium sulphate with calcium carbonate. The rate of sulphate removal was influenced by the BaCO₃ concentration and the cation associated with sulphate, and increased with increasing BaCO₃-concentration. BaCO₃ can only be used for removal of sulphate that is associated with calcium, as calcium is needed to remove the added carbonate associated with the barium cation. Sulphate removal was only marginally influenced by alkalinity. Sulphide can be stripped with CO₂ from a BaS-solution. The (CO₂ dosed/sulphide removed) molar ratio was close to unity for the first 50% of sulphide in solution. The stripped H₂S-gas can be absorbed into zinc acetate. BaSO₄ and CaCO₃ can be converted simultaneously to BaS and CaO, respectively at an optimum temperature of 1050°C. The CaCO₃/BaSO₄ molar ratio has little influence on the yield of BaS. The running cost of the barium carbonate process for the removal of 2 g/L of sulphate totalled ZAR1.28/m³ (US$1.00 = ZAR7.0, Feb 2007), the capital redemption cost was R1.08/m³, and the value of the products (water and sulphur) totalled R2.76/m³.     

寺湾矿矿井水除铁锰过程中的影响因素分析

对寺湾矿矿井水除铁、锰过程中的影响因素进行了试验分析,结果表明:影响铁的去除因素主要是混凝剂及其投药量,聚合氯化铝的最佳投药量为20mgL;影响锰的去除因素主要是滤料和滤速,采用高锰酸钾浸泡的锰砂作为滤料,滤速6～8mh,出水铁锰含量小于0.1mgL,满足回用要求,而且滤料成熟期只有1～2d,是一种高效的除锰技术。     

Adsorptive Performance of Surface-Modified Montmorillonite in Vanadium Removal from Mine Water

Montmorillonite modified with hexadecyltrimethylammonium bromide was used to remove vanadium (V) from synthetic and real mine water. Fourier transform infrared, X-ray diffraction, and scanning electron microscopy were used to characterise the adsorbent before and after adsorption, while the amount of V adsorbed was determined by ICP-OES. Batch adsorption was evaluated for dissolved V concentrations of 50–320 mg/L and V tailings seepage water from a South African mine. Adsorption capacity was affected by solution pH, temperature, sorbent mass, and the initial concentration. Electrical conductivity of the mine water before and after adsorption was measured to estimate the total dissolved solids. Equilibrium isotherm results revealed that V sorption follows the Freundlich isotherm, indicating that the sorbent surface was heterogeneous. A pseudo-second order kinetic model gave the best fit to the kinetic experimental data. The results of this study allow us to predict uptake efficiency of South African montmorillonite for V removal from mine water. However, the best adsorbent for the uptake of V or other contaminants will depend on the effluent to be treated.     

石灰混合溶液除氟工艺在矿井水中的应用技术探讨

文章对五阳煤矿矿井水氟化物的去除工艺进行了对比论述,得出现阶段煤矿矿井水含氟量在3mg/L以下时采用石灰混合溶液除氟工艺十分可行的结论。     

岩体突水通道形成过程中应力-渗流-损伤多场耦合机制

突水通道形成的渐进性破坏过程是煤矿突(透)水机理研究的关键问题,采动扰动和地下水双重作用下岩体的持续渗流-损伤行为导致破裂通道最终形成.采用可考虑地下水作用下岩体拉剪和压剪双重破坏准则的计算程序,真实再现承压含水层与巷道之间隔水岩体的采动裂隙萌生、扩展、贯通直至破裂通道形成的灾变演化过程,通过对岩体应力场、渗流场和损伤场的耦合演化过程进行分析,实现了对突水通道形成轨迹的准确定位,揭示了突水通道形成过程中岩体应力-渗流-损伤的耦合机制.数值实验结果表明:采动影响下持续的应力-渗流-损伤耦合作用诱发岩体强度降低导致突水通道最终形成,隔水岩体历经了群裂纹萌生、扩展和贯通的渐变过程;通道贯通前,岩体破裂损伤能量激增,通道部位岩体剪应力急剧下降,渗透系数和流量则急剧上升,各物理场均孕育了不同程度的突水前兆信息.     

Mine Water as a Resource: Selective Removal and Recovery of Trace Antimony from Mine-Impacted Water

The objective of this study was to evaluate the feasibility of combined modular processes to selectively remove Sb from mine-impacted waters in an Arctic environment in order to fulfil local environmental criteria for discharged waters. Novel ion exchange, selective extraction and ultrafiltration, electrocoagulation, and dissolved air flotation technologies were investigated, individually or in combination, from the laboratory- to pilot-demonstration scale. Laboratory-scale testing using Fe₂(SO₄)₃ precipitation, ion exchange resin, selective ion extraction and ultrafiltration, and electrocoagulation with or without subsequent dissolved air flotation indicated that any of the methods are potentially applicable to Sb removal from mine water. The observed differences between Sb and As removal efficiency by ion exchange resin illustrated the need for Sb-specific removal and recovery technologies. Techno-economic analyses showed that treatment of mine water using electrocoagulation-dissolved air flotation yields the lowest comparative life-cycle cost of examined technologies. Results demonstrated increased Sb attenuation efficiency using either electrocoagulation-dissolved air flotation or selective extraction and ultrafiltration, even when treating only 50% of the mine-impacted water, compared with conventional Fe₂(SO₄)₃ precipitation from mine water. Additional investigation is necessary to characterize the long-term stability of the mineral phases in Sb-containing solid residues and to inform selection of Sb recovery methods and utilisation or final disposal options for the residual materials.

     

Removal of Ions and Acidity from Acid Mine Water Using Transformed Fly Ash

Fly ash obtained from a coal combustion thermal electric power plant was reacted with NaOH at 100 °C for 24 h to synthesize zeolite. Shaker flasks experiments were conducted to assess whether fly ash or fly ash zeolite (FAZ) could be used to treat acidic mine water. The FAZ was used to treat the mine water at doses of 5–60 g/L; the FAZ increased pH from 2.76 to as high as 7.51 and removed most of the Ca and Mg hardness and acidity from the mine water, though it did not affect sulphate concentrations. The cation exchange capacity of the FAZ was regenerated using NaCl. After six regeneration/reuse cycles, the FAZ was less effective but still capable of increasing pH and removing substantial hardness. In contrast, fly ash was not effective in removing hardness or acidity, and instead released ions into the mine water.     

Treatment of Mine Water for Sulphate and Metal Removal Using Barium Sulphide

Abstract.   The integrated barium sulphide process consists of: preliminary treatment with lime, sulphate precipitation as barium sulphate, H₂S-stripping, crystallization of CaCO₃, and recovery of barium sulphide. Our tests showed that during lime pre-treatment, sulphate was lowered from 2 800 mg/L to 1 250 mg/L by gypsum crystallization; metals were precipitated as hydroxides. The BaS treatment then lowered sulphate to less than 200 mg/L. Sulphide was lowered from 333 to less than 10 mg/L (as S) in the stripping stage, using CO₂ gas for stripping. The stripped H₂S-gas was contacted with Fe (III)-solution and converted quantitatively to elemental sulphur. The alkalinity of the calcium bicarbonate-rich water was reduced from 1 000 to 110 mg/L (as CaCO₃) after CO₂-stripping with air due to CaCO₃ precipitation. Fe (II), after sulphur production, was re-oxidized to Fe (III) using an electrolytic step. The running cost of the BaS process is R2.12/m³ (US$1 = SAR6.5) for the removal of 2 g/L of sulphate.     

Adsorption Properties of Modified Saponite in Removal of Heavy Metals from Process Water

Journal of Mining Science - The adsorption properties of electrochemically and thermally modified saponite relative to heavy metals are analyzed. The tests have found the efficient use and...     

浅谈金属矿山酸性废水处理工艺

随着国民经济的快速发展,人类对金属矿山的开采力度加大。在金属矿山开采过程中会对采矿区周边生态环境造成影响,其中硫化矿系（硫铁矿及多金属硫化矿等）经过风化、淋溶等形成的酸性矿山废水（acid mine drainage,AMD）对环境的影响尤为严重。AMD的治理是矿山生态环境治理的重中之重。阐述了酸性矿山废水的来源,总结了目前较为有效的处理工艺,可为AMD治理提供参考。     

浅析物理化学法处理矿井水

通过实例论述了物理化学法处理矿井水的工艺及其所产生的经济、社会和环境效益，供煤矿矿井水处理工作借鉴。     

矿山井下排水工艺改造

为避开供电部门对企业实行峰谷电价，矿业企业实施工艺改造，避开峰段排水，在保证安全的前提下实现了电网经济运行。     

Bench-Scale and Pilot-Scale Treatment Technologies for the Removal of Total Dissolved Solids from Coal Mine Water: A Review

Coal mine water (CMW) is typically treated to remove suspended solids, acidity, and soluble metals, but high concentrations of total dissolved solids (TDS) have been reported to impact the environment at several CMW discharge points. Consequently, various states have established TDS wastewater regulations and the US EPA has proposed a benchmark conductivity limit to reduce TDS impacts in streams near mining sites. Traditional CMW treatment effectively removes some TDS components, but is not effective in removing major salt ions due to their higher solubility. This paper describes the basic principles, effectiveness, advantages, and disadvantages of various TDS removal technologies (adsorption, bioremediation, capacitive deionization, desalination, distillation, electrochemical ion exchange, electrocoagulation, electrodialysis, ion exchange, membrane filtration, precipitation, and reverse osmosis) that have at least been tested in bench- and pilot-scale experiments.     

金矿氰化废水组合催化体系催化氧化除氰研究

筛选了Na_2S·9H_2O+Cu~(2+)作为组合催化氧化除氰体系,对金矿含氰废水进行除氰试验,结果表明,该组合催化体系处理某矿山实际含氰废水,除氰率达99%以上,经一级处理即可达标排放。通过分析铜离子在含氰溶液中的存在形态及其对活性炭吸附容量的影响和Na_2S·9H_2O对浸铜碳吸附容量的影响,探讨了Na_2S·9H_2O+Cu~(2+)组合催化体系的催化除氰机理。     

Arsenic Removal from Mine Waters with Sorption Techniques

Potential low-cost sorption materials (mostly industrial by-products) were screened for removal of arsenic from mine effluent water. First, the maximum adsorption capacities were determined in batch tests with various liquid to solid ratios. The highest arsenic sorption capacity, 46 mg As/g of sorption material, was measured for cast iron chips. The most promising materials were also studied in batch tests that assessed the reaction kinetics and in kinetic column tests for their behavior in a filter or reactive barrier application. The column tests revealed the cast iron chips caused clogging in the percolation column when operating with real mine water. A commercial ferric oxi-hydroxide sorption material developed for As removal for drinking water showed good As removal in the column tests. Around 10,000 bed volumes of mine process water containing 2 mg/L of arsenic was treated with this material, and treated water concentrations ranged between 0 and 0.05 mg/L before breakthrough. The measured adsorption capacity for the commercial ferric oxi-hydroxide sorption material was 8.3 mg As/g.     

某铀矿山废水中铀的去除试验研究

我国某铀矿山废水成分分析结果表明,废水中主要污染成分为铀,用离子交换树脂吸附处理铀,并进行了相关条件试验,条件试验内容包括离子交换树脂型号选择、树脂吸附、淋洗和合格液沉淀等条件试验。试验结果表明：用离子交换树脂处理该铀矿山废水中铀,工艺可行,处理后废水中铀浓度≤0.3mg.L_^-1,且废水中铀得到回收利用。试验用408(II)树脂进行离子交换吸附,用1M NaCl + 5 g.L_^-1 NaHCO₃作淋洗剂进行淋洗,淋洗效果好;树脂饱和吸附容量达到18 mg U.mL_^-1R,淋洗合格液中铀浓度峰值>20 g.L_^-1,贫树脂残余铀容量<0.5 mgU.mL_^-1R,沉淀回收得到的“111”产品达到国家标准。     

活性剂对矿井除尘水雾化效果的影响

为了能使除尘用水的性能满足防治煤尘的要求,通过选取不同浓度的表面活性剂进行水特性的复配研究,得出了水雾化效果、表面张力与不同表面活性剂及复配质量分数之间的关系。其研究结果表明:在复配表面活性剂质量分数为0.04%且阴离子型活性剂A与非离子型活性剂B的质量比为4:2时,对水特性的影响程度达到最大,其适合捕捉呼吸性粉尘的雾滴百分比达到69%左右,经高庄煤矿综放工作面现场应用,除尘效率达到了85%以上,大幅度改善了井下的工作环境。     

矿山酸性水中浸矿细菌的筛选及除铁效果

细菌浸矿在矿石综合利用和生态环境保护方面具有重要意义。从兖州煤矿酸性矿井水中筛选、分 离到1株具有嗜酸、氧化Fe2+的浸矿细菌,编号SKDYJ-1。通过对其16S rDNA 基因序列分析,发 现该菌株16S rDNA 基因序列与Pantoea agglomerans P1SAA（FJ611818）的同源性高达98% ,为嗜酸成团泛菌。对该菌株形态、生长特性、Fe2+氧化率进行了研究,结果表明：菌株 SKDYJ-1细胞呈杆状,革兰氏阴性,最适生长温度为30 ℃,在25 ℃、30 ℃以及35 ℃条件下培 养,菌株SKDYJ-1对Fe²⁺的最大氧化率分别为2.79%、6.52% 和5.59%,具有较高的浸矿能力。     

煤矿矿井水污泥处理存在的问题及对策

为了掌握我国煤矿矿井水污泥处理现状及存在的问题,对全国50多座煤矿的矿井水污泥处理设施进行了调研分析。结果表明:大部分煤矿建有矿井水污泥处理设施,但是污泥处理水平参差不齐,最终处置利用途径狭窄。通过加强针对性研究、提高自动化程度、完善标准规范、开拓最终处置方式和资源化利用途径、政策引导与监督,可以有效改善污泥的处理和处置状况。     

煤矿酸性老空水形成机制及其处置技术研究

依据煤矿老空区空间分布特性,对形成老空水的聚水空间、水源及通道等影响因素探讨分析。根据老空区形成的空间结构不同,采用不同的方法计算评价老空区积水量大小,分析其积水过程特点。对老空水的酸性演化过程、水质变化机理及其影响因素综合分析。针对老空区水酸性特性,探讨老空水处置技术,为煤矿老空水资源的处置利用提供新的思路。