某铁矿尾矿库酸性废水处理试验研究

介绍了使用两段中和法处理矿山酸性废水,即首先用矿物或废渣作中和剂将废水的pH值提高到4.0左右,再用石灰乳进行中和。在实验室研究的基础上,对某铁矿尾矿库酸性废水采用两段中和法进行工程试验。试验结果表明,滤料高度为60 cm,用5%的石灰乳作中和剂,石灰用量为0.5~0.8 kg/m3,絮凝剂投加量为2×10-6,出水pH值达到6~8,出水水质指标达到国家排放标准。两段中和法比一段法节省石灰用量,节约处理费用。     

从V2O5生产废水中脱除氨氮的研究

用石灰调节pH-蒸气吹脱法处理V2O5产生的高浓度氨氮废水．结果表明：在废水氨氮含量高达14．5g／L的情况下．用石灰调节pH=11．8，吹脱温度95℃以上．蒸气吹脱3．5h，可使废水的氨氮脱除率达99．5％以上，处理后的废水氨氮含量符合国家排放标准．氨氮回收率达93％，回收的氨水可用于沉钒工艺．处理后的废水可循环利用．     

矿山含铜酸性废水处理研究

针对矿山含铜酸性废水特点,采用石灰中和沉淀法和石灰调pH—铁屑置换—石灰沉淀法分别进行试验,结果表明,石灰调pH—铁屑置换—石灰沉淀法不仅可以使废水经处理后达到排放标准,而且废水中的大部分铜资源得以回收利用,具有较好的经济效益和环境效益。     

洗涤冶炼烟气产生的含砷酸性废水的利用及处理

以洗涤冶炼烟气含砷酸性废水为原料,采用CaO和NaOH分段中和后加入硫酸铜制备得到亚砷酸铜.一段中和时每升废水加入氧化钙16g,二段中和时加入氢氧化钠调节废水pH值为6.0,中和后废水中Pb、Cu、Fe、Mg杂质去除率达到90%以上,砷损失率约为7%.按照铜砷物质的量之比2:1,在中和后废水中加入硫酸铜,采用氢氧化钠溶液调节溶液pH值为8,经过过滤、洗涤、干燥得到亚砷酸铜,其砷转化率达到98.2%.制备亚砷酸铜后的废水采用石灰-聚合硫酸铁絮凝处理,当石灰调节废水pH值为9.0、铁砷物质的量之比为8:1时,处理后废水中砷含量为0.30 mg/L,达到了国家废水排放标准(GB 8978-1996).     

某矿山含铜酸性废水处理的工业实践

很多有色金属矿山在开发过程中,会产生大量含铜酸性废水。由于酸性废水含铜浓度差异性较大,采取的处理工艺也会有所不同。本文针对某矿山含铜酸性废水进行了大量的工业试验研究,结果表明：较高浓度含铜酸性废水可采取硫化法回收铜金属,再经环保中和处理后循环利用,可大量减少中和渣产生量,降低环保处理成本,有显著的经济、环保效益。同时,为了防范极端气候下的环境风险,该矿山还建设了足够处理能力的备用石灰中和处理系统以及应急液碱（片碱）加药系统,以供同类矿山参考、借鉴。     

利用尾矿碱度处理矿山酸性废水的研究

德兴铜矿矿山酸性废水中sO24-含量大,如采用常规的石灰中和法,中和过程中产生的硫酸钙结垢严重,给工艺运行造成很多困难.利用选矿生产中产生的尾矿溢流液,采用二段中和工艺,在pH4的酸性条件下,充分发挥尾矿溢流液中碳酸钙的碱度中和酸性废水,不但节省石灰碱性药剂,而且达到了矿山酸、碱废水以废治废的目的.     

石灰絮凝法去除矿坑废水中锰离子的研究

采用石灰絮凝法对福建潘洛铁矿矿坑废水中Mn离子进行了去除试验研究。石灰用量为150 g/m³, 阴离子PAM用量为0.5 g/m³, 98%硫酸用量为20 g/m³, 处理后出水达到GB8978-1996一级排放标准。通过对石灰沉淀除锰机理分析, 锰从废水中沉淀析出适宜的pH值应大于8.5, 而要使处理后废水锰含量达标(Mn含量低于2.0 mg/L), 则废水pH值应控制在10.0以上。实验室试验研究结果为后续的工程设计提供了较为合理的工艺流程。     

铅锌选矿废水处理自控系统设计及应用

针对铅锌矿选厂人工简单处理废水带来的水质差、指标不稳定、无法连续回用等问题,设计了一种高效的选矿废水处理自动化系统。根据废水的处理方法为沉淀-石灰中和法-曝气法工艺,采用了先进的自动化集成系统,并通过多种算法优化各项环节的PID控制系统,使选矿废水稳定达到废水排放指标,并循环利用了可回收矿物泥以及水资源,最后,设计整体的自动化监控系统软件,提升废水处理的管理水平。以某铅锌矿选矿为例进行工程应用,结果表明,废水处理过程的全面自动化进行工程应用,降低人力成本,出水水质达标,可以为偏僻的矿山实现了水的循环使用,保证了生产的稳定。     

利用尾矿碱度处理矿山酸性废水的研究

德光铜矿矿山酸性废水中SO4^2-含量大,如采用常规的石灰中和法,中和过程,中产生的硫酸钙结垢严重,给工艺运行造成银多困难,利用选矿生产中产生的尾矿溢流液,采用二段中和工艺,在pH4的酸性条件下,充分发挥尾矿溢流液中碳酸钙的碱度中和酸性废水,不但节省石灰性药剂,而且达到了矿山酸、碱废水以废治废的目的。     

碱性含铀废水处理试验研究

采用石灰去除CO_3~(2-)—硫酸亚铁中和深度除铀—氯化钡除镭—污渣循环减容工艺处理碱性含铀废水,考察了石灰、硫酸亚铁、氯化钡用量等条件对铀、镭的去除效果。试验结果表明:当Ca(OH)_2用量为化学计量1.1倍、FeSO_4·7H_2O质量浓度为2.0g/L、氯化钡质量浓度为60mg/L时,铀质量浓度降至0.05mg/L以下,镭活度浓度降至1.0Bq/L以下,pH可控制在8.0左右,处理后的废水可达标排放。     

Limestone Neutralisation of Arsenic-Rich Effluent from a Gold Mine

Traditionally acid mine water is neutralised with lime. Limestone is a cheaper alternative for such applications. A case study showed that limestone can be used effectively to replace lime for the neutralization of arsenic rich acid water. The cost of limestone treatment is 45.8% less than that of lime. The acidity can be removed from 33.5 to 0.06 g/L (as CaCO₃). The study also showed no significant differences in the TCLP characteristics of the resultant sludge when water is treated with lime or with limestone. Sludge from the limestone treatment process can be disposed of on a non-hazardous landfill site. An erratum to this article can be found at     

Neutralizing Coal Mine Effluent with Limestone to Decrease Metals and Sulphate Concentrations

Abstract.   This paper describes pilot scale tests of a novel process for the neutralisation of acidic mine water. Leachate from a waste coal dump was neutralised with limestone, and iron, aluminium, and sulphate were removed. Specific aspects studied were: the process configuration; the rates of iron oxidation, limestone neutralisation, and gypsum crystallisation; the chemical composition of the effluents before and after treatment; the efficiency of limestone utilisation; and the sludge solids content. The acidity was decreased from 12,000 to 300 mg/L (as CaCO₃), sulphate from 15,000 to 2,600 mg/L, iron from 5,000 to 10 mg/L, aluminium from 100 to 5 mg/L, while the pH increased from 2.2 to 7.0. Reaction times of 2.0 and 4.5 h were required under continuous and batch operations respectively for the removal of 4 g/L Fe (II). The iron oxidation rate was found to be a function of the Fe (II), hydroxide, oxygen, and suspended solids (SS) concentrations. The optimum SS concentration for iron oxidation in a fluidised-bed reactor was 190 g/L. Up-flow velocity had no influence on the rate of iron oxidation in the range 5 to 45 m/h. Sludge with a high solids content of 55% (m/v) was produced. This is high compared to the typical 20% achieved with the high density sludge process using lime. It was determined that neutralisation costs could be reduced significantly with an integrated iron oxidation and limestone neutralisation process because limestone is less expensive than lime, and a high-solids-content sludge is produced. Full scale implementation followed this study.     

石灰石和方解石预处理酸性含氟废水的试验研究

稀有金属矿冶炼厂废水成分复杂、酸性强、含氟高、含有多种重金属离子。采用天然石灰石或方解石对其进行中和沉淀预处理, 使pH值升至2.5～3.5, 可以去除大部分氟;然后再投加石灰乳和混凝剂PAM, 使其pH值达8.5 左右, 这样能有效地去除其中的氟和重金属离子。该废水处理工艺形成的化学沉淀少、操作简单方便, 与传统的石灰乳中和法相比, 该工艺能较大幅度地降低酸性废水的处理成本。     

Use of activated silica sol as a flocculant in the treatment of acid mine drainage to promote sludge stability

The most common treatment for acidic drainage is lime neutralization. The process involves neutralization and precipitation of a metal hydroxide-gypsum sludge using a flocculant, generally Percol. In the short term, the sludge is stable, but in the long term, any tendency of pH to drop can re-dissolve metal hydroxides and contaminate the surrounding area and groundwater. The use of activated silica sol, an inorganic silicate polymer used in municipal water treatment, as a replacement to Percol is investigated to improve long term stability of sludge. Silica sol is an effective flocculant, has neutralization potential, and forms metal–silica bonds more resistant to pH variation than metal hydroxides. Various mine effluents and simulated solutions were treated with lime and silica sol or Percol to pH 9–10. Results show that settling characteristics with low dosages of silica sol and Percol are similar. Leachability tests showed that the stability of the sludge improved when silica sol was used for one cycle, and after 4 cycles results were similar to Percol. Activated silica sol, therefore, has the potential to increase sludge stability in a single stage lime treatment process.     

加药方式对铜萃余液中和处理的影响

本文验证一段石灰中和工艺,通过调整加药方式、药剂混配、用水类型、加药次数等方式对铜萃余液的pH值的影响,初步对各种中和工艺下的中和渣产量及药剂成本进行分析。结果表明,湿法加药方式比干法的加药方法对铜萃余液的中和效果更好。与现有中和工艺比较,采用石灰乳分两段中和工艺具有药剂成本低和时间短特点,而石灰石-石灰两段中和工艺属于石灰石药剂耗量易控制,理论渣量较小,综合药剂成本较低。      

湿法回收氯化石灰中和渣中的锗

研究了回收氯化石灰中和渣中的锗的工艺,采用热水洗涤除钙、稀盐酸浸出锗除钙,洗涤浸出后的渣用两段逆流碱浸出锗.酸浸出液与一次碱浸出液混合并调节pH为2~2.5,用栲胶沉淀锗,焙烧沉淀渣得到锗精矿.采用此工艺从氯化石灰中和渣到锗精矿,锗的回收率可以达到90%以上.     

Water Cover Over Mine Tailings and Sludge: Field Studies of Water Quality and Resuspension

Flooding is considered one of the best available technologies for long term storage of acid generating mine waste when suitable site-specific conditions exist. There is, however, a concern that oxidation may still occur. In cases where lime neutralization sludge and reactive sulfide tailings are co-disposed in the tailings pond, wind-induced waves could resuspend the waste and negatively impact the quality of the water cover. Studies were undertaken at the Noranda Inc. Heath Steele Lower Cell tailings impoundment, located in northeastern New Brunswick, Canada, 50 km northwest of city of Miramichi. The stored material in the cell consisted of unoxidized tailings with small amounts of sludge. The 90 ha impoundment acted as a polishing pond, prior to the discharge of final effluent. The pond was keptalkaline (pH of 8.5-10.5) in order to meet regulated discharge limits. On some windy days when the Lower Cell experienced turbulent water conditions, the final effluent exceeded the suspended solids water quality standard of 25 mg/L. The dry mass of suspended sediment measured in 1999 ranged from 1.5 to 434 mg with relatively more material (> 100 mg) being suspended under shallow water cover (= 1 m). Both x-ray diffraction and scanning electron microscopy analyses indicated that the suspended material was mostly lime neutralization sludge and other material composed primarily of calcite and brucite and coatings of aluminum, iron, zinc and manganese hydroxides. Solubility considerations of the carbonate system confirmed that the water cover was supersaturated with respect to calcite. The results suggest that sludge and tailings re-suspension and precipitation of solid phases in the water cover likely combined to produce the observed, occasionally high total suspended solids concentration.     

采用高密度污渣返回法处理铀矿山酸性废水的研究

介绍了采用高密度污渣返回法处理铀矿山酸性废水工艺流程。该流程与常规法比较,有以下优点:污渣沉淀速度快,压缩性能好,w (固体)高,没有返溶现象,并且石灰用量减少约20% 。从而解决了普通石灰中和法产生大量污渣及难以处置的问题     

高密度泥浆法处理硫铁矿废水试验研究

高密度泥浆法(HDS法)是一种区别于传统石灰法、具有独特原理和特点的中和处理技术。采用高密度泥浆法对新桥硫铁矿废水进行了处理试验,研究了pH值、曝气、反应时间、沉淀时间、絮凝剂、底泥回流等对处理效果的影响。试验结果表明,采用HDS法,引入曝气工艺可使处理水质稳定达到排放标准,并得到了HDS法处理新桥硫铁矿废水的工艺参数,为工程设计提供了科学依据。     

Reclamation of Abandoned Coal Mine Waste in Korea using Lime Cake By-Products

Abstract.  There are hundreds of abandoned coal mines in Korea's steep mountain valleys. Enormous amounts of coal waste from these mines were dumped on the slopes, contaminating streams with sediment and acid mine drainage. A limestone slurry by-product (lime cake), which is produced during the manufacture of soda ash, was investigated for its potential use in reclaiming the coal waste. The lime cake is fine grained, has low hydraulic conductivities (10^-8 to 10^-9 cm sec^-1), high pH, high electrical conductivity, and trace amounts of heavy metals. A field experiment was conducted; each plot was 20 x 5 m in size on a 56% slope. Treatments included a control (waste only), lime (CaCO₃), and lime cake. The lime requirement (LR) of the coal waste to pH 7.0 was determined; treatments consisted of adding 25, 50, and 100% of the LR. The lime cake and lime were applied either as a layer between the coal waste and topsoil or mixed into the topsoil and waste. Each plot was hydroseeded with grasses, and planted with trees. In each plot, soils, surface runoff, and subsurface water were collected and analyzed, and plant cover was measured. Lime cake treatments increased the pH of the coal waste from 3.5 to 6, and neutralized the pH of the runoff and leachate of the coal waste from 4.3 to 6.7. Moreover, the surface cover of seeded species was significantly increased; sufficient acidity in the coal waste was neutralized in the 25% LR plots to allow seed germination.