共查询到20条相似文献，搜索用时 62 毫秒
1.
Heriberto Bustamante Leonard J. Warren 《International Journal of Mineral Processing》1984,13(1):13-28
Laboratory batch flotation tests were carried out to determine the effect of grain size on the recovery of four Australian bituminous coals of high and low rank. The flotation concentrates, taken over successive time intervals, and the tailings, were sized and the recovery-size curves plotted. A method was developed for determining the proportions of liberated and composite grains in the various flotation products. Flotation tests were carried out in the presence of methylisobutylcarbinol (MIBC) and MIBC + kerosene. The shapes of the recovery-size curves depended on the rank of the coal and whether or not kerosene was present. The variation of the recovery with size was explained in terms of the joint effect of rank and size on the floatability of composite grains. 相似文献
2.
Shear-flocculation/flotation and carrier flotation are methods by which fine mineral values are aggregated and then recovered by flotation. The aggregates formed have better floatabilities. Without prior treatment ahead of flotation, significant quantities of fines are lost in tailings. An overview of the problems associated with fine particles is presented. Like froth flotation, the mechanisms of shear-flocculation and carrier flotation are governed by physical, chemical and geometrical variables. The present paper deals with the effects of these variables on shear-flocculation and carrier flotation, based on a detailed literature review. 相似文献
3.
国内外“人工矿床”研究现状与前景 总被引：3，自引：0，他引：3
“人工矿床”主要是指废石及尾矿等能被重新利用的资源，在富矿资源日益减少的今天，贫矿资源，废石及尾矿等非传统资源的开发利用越来越受到重视，目前，国内外主要从物质再回收和物质转移两个方面对废石和尾矿的综合利用进行研究。国外已利用细菌浸出等先进的矿物加工工艺从低品位的含铜和含金的废石和尾矿中回民铜和金，利用已无回收价值的尾矿加工制造水泥，陶瓷，玻璃等新型材料，国内主要利用重选，磁选，浮选，化学选矿联合工艺流程回民铁，铜，金等尾矿中的有用元素,利用废石，尾矿作建筑石料或加工制造砖，混凝土，陶瓷等建筑材料。 相似文献
4.
金川镍矿浮选尾矿数量巨大,含有相当可观的有价金属,其中有价金属的回收受到越来越多的关注。金川老尾矿库尾矿砂中Ni和Cu赋存状态复杂,水溶性矿物态、可交换离子态、碳酸盐态、结晶度较差的Fe氧化物态、结晶度较好的Fe氧化物态、硫化物态和残渣态中都含有数量不等的有价金属Ni和Cu;尾矿砂风化作用释放的金属阳离子大多数在发生氧化的硫化物位置原位发生水解沉淀形成次生矿物,有价金属Ni和Cu在尾矿库中没有发生明显的富集。金川镍矿尾矿砂中Ni和Cu适于用化学酸溶浸出的方法进行二次回收。 相似文献
5.
《Applied Geochemistry》2004,19(11):1855-1864
The Coquimbo region has been one of the richest producers of Cu, Au and Hg in Chile, and some of the deposits have been mined almost continuously since the 16th century. To assess the potential environmental contamination in this region, the authors measured the concentration of Cu, As, Cd, Zn and Hg in samples of stream and mine waters, stream sediments, soils, flotation tailings, and mine wastes in the Andacollo (Cu, Au, Hg) and Punitaqui (Cu–Au, Hg) districts. The concentration of Hg in the atmosphere in these districts were also measured. Although contamination is strongly controlled by the ore in each district, metal dispersion is modified by the degree of metallurgical processing efficiency as shown by the outdated Cu flotation system at Andacollo (stream sediments Cu 75–2200 μg/g). Conversely, more efficient procedures at Punitaqui resulted in less stream contamination, where stream sediments contained Cu ranging from 110–260 μg/g. However, efficient concentration by flotation of a given metal (e.g. Cu) may lead to the loss of another (e.g. Hg up to 190 μg/g in the tailings at Punitaqui), and therefore, to contamination via erosion of the tailings (downstream sediments Hg concentrations up to 5.3 μg/g). Continued use of Hg for Au amalgamation at Andacollo has led to significant contamination in stream sediments (0.2–3.8 μg/g Hg) and soils (2.4–47 μg/g Hg). Communities in this region are underdeveloped, and decades of inefficient treatment of flotation tailings and waste-rock stock piles has resulted in significant contamination of the surrounding landscape. 相似文献
6.
7.
J.A. Frew 《International Journal of Mineral Processing》1982,9(2):173-189
The detailed flotation behaviour observed in industrial zinc cleaning circuits at Broken Hill differs markedly from that commonly reported for rougher and scavenger flotation. Flotation is strongly influenced by solids to liquid ratio (pulp density) and the behaviour can be described by an exponential relationship between the flotation rate coefficient and the pulp density in each cell. The dependence on pulp density is largely independent of mineral type but does depend upon particle size. The largest variation is observed for coarse particles.The observations are of considerable significance to control of circuit performance. The results of simulations incorporating the dependence of rate coefficient upon pulp density differ substantially from those obtained from conventional models which assume constant rate coefficients. 相似文献
8.
R.H. Yoon 《International Journal of Mineral Processing》1981,8(1):31-48
The flotation of chalcopyrite and sphalerite from copper and copper-zinc ores has been achieved without using thiol-type collectors. Typically, a sulfide ore sample is first treated with sodium sulfide either during grinding or during the preflotation conditioning period, and then the chalcopyrite is floated with frother alone. With a copper-zinc ore, sphalerite is subsequently floated from the chalcopyrite tailings by activating it with copper sulphate. Results of the collectorless flotation tests are comparable to those obtained by using thiol collectors. The mechanisms of selective collectorless flotation are discussed on the basis of differences in the solubilities of sulfide minerals. 相似文献
9.
Both froth flotation and centrifugal concentration were used to pre-concentrate the oil sands froth treatment tailings prior to the recovery of heavy minerals (titanium and zirconium minerals). Over 90% of the heavy minerals were recovered into a bulk flotation concentrate that was about 50% of the feed mass at 85 °C without any reagents. The same recoveries were obtained at 50 °C with the addition of NaOH and/or sodium oleate. However, the flotation concentrate also recovered over 90% of the residual bitumen and much of the clays/slimes. Subsequent treatment of the flotation concentrate such as dewatering and bitumen removal would be difficult due to these residual bitumen and clays. On the other hand, a SB40 centrifugal concentrator recovered over 85% of the heavy minerals but less than 30% of the residual bitumen. With improved liberation the recovery of the residual bitumen into the concentrate could be further reduced. The particle sizes of the SB40 concentrates were also larger than the flotation concentrates, making subsequent processing much easier. 相似文献
10.
《International Journal of Mineral Processing》2005,77(3):165-185
The elitist non-dominated sorting genetic algorithm with the modified jumping gene operator (NSGA-II-mJG) is used to optimize the performance of froth flotation circuits. Four example optimization problems (Mehrotra and Kapur, 1974; Green, 1984; Dey et al., 1989) [Mehrotra, S.P., Kapur, P.C., 1974. Optimal–sub-optimal synthesis and design of flotation circuits. Sep. Sci. 9, 167–184; Green, J.C.A., 1984. The optimization of flotation networks. Int. J. Miner. Process. 13, 83–103; Dey, A.K., Kapur, P.C., Mehrotra, S.P., 1989. A search strategy for optimization of flotation circuits. Int. J. Miner. Process. 26, 73-93.] of varying complexity are solved using single-objective functions. In one example, the overall recovery of the concentrate stream is maximized for a desired grade of the concentrate and a fixed total cell volume. The interconnecting cell linkage parameters (fraction flow rates) and the mean cell residence times are the decision variables. In all these cases, the optimal solutions obtained using NSGA-II-mJG are superior to those obtained by earlier techniques (which converged to local optimal solutions). Thereafter, a few two-objective optimization problems are solved. In these, the performance of the circuit is optimized, and simultaneously, the number of connecting streams is minimized so as to give simple circuits. Pareto optimal sets of equally good (non-dominating) solutions are obtained. This is probably the first study involving the multi-objective optimization of flotation circuits with one aim being to simplify them. 相似文献
11.
Bogusław Woźniakowski 《International Journal of Mineral Processing》1976,3(3):281-284
Based on the results of large-scale industrial experiments, the value of utilizing flotation tailings for the production of cellular concrete is discussed. The paper is confined to the technical and ecological aspects of the process. 相似文献
12.
Hydraulic Conductivity of Fly Ash-Amended Mine Tailings 总被引：1，自引：1，他引：0
Sultan A. Alhomair Mohammad H. Gorakhki Christopher A. Bareither 《Geotechnical and Geological Engineering》2017,35(1):243-261
The objective of this study was to evaluate the effect of fly ash addition on hydraulic conductivity (k) of mine tailings. Mine tailings used in this study were categorized as synthetic tailings and natural tailings; two synthetic tailings were developed via blending commercially-available soils and natural tailings were collected from a garnet mine located in the U.S. Two fly ashes were used that had sufficient calcium oxide (CaO) content (17 and 18.9 %) to generate pozzolanic activity. Hydraulic conductivity was measured on pure tailings and fly ash-amended tailings in flexible-wall permeameters. Fly ash was added to mine tailings to constitute 10 % dry mass of the mixture, and specimens were cured for 7 and 28 days. The influence of fly ash-amendment on k of mine tailings was attributed to (1) molding water content and (2) plasticity of the mine tailings. Tailings that classified as low-plasticity silts with clay contents less than 15 % exhibited a decrease in k when amended with fly ash and prepared wet of optimum water content (w opt ). Tailings that classified as low-plasticity clay exhibited a one-order magnitude increase in k with addition of fly ash for materials prepared dry or near w opt . The decrease in k for silty tailings was attributed to formation of cementitious bonds that obstructed flow paths, whereas the increase in k for clayey tailings was attributed to agglomeration of clay particles and an overall increase in average pore size. The results also indicated that the effect of curing time on k is more pronounced during the early stages of curing (≤7 days), as there was negligible difference between k for 7 and 28-days cured specimens. 相似文献
13.
14.
J.C.A. Green 《International Journal of Mineral Processing》1984,13(2):83-103
The generalised optimisation of a flotation network is studied by means of using variable connections (structural parameters) and variable enhancement factors which are used instead of a flotation model to describe the separation process. The enhancement factors are functions of variables affecting the flotation process. These functional relationship may be derived by means of using a flotation model. Bounds are placed on the enhancement factors by means of either using a flotation model or by inspection of existing pilot or commercial plant data. These bounds, together with external, system and mass balance constraints and an appropriate objective function, define the general optimisation problem for a flotation network.The optimisation problem above may be solved by non-linear programming methods, however, it is easily transformable into a Linear Programme which is easy to solve. The procedure has been applied to a flotation circuit comprising three banks of cells for which an optimal set of connections and enhancement factors has been computed for varying constraints.A simulation procedure based on a gamma flotation model has been applied to one of the optimal circuits so as to compute the flotation variables. 相似文献
15.
A.R. Laplante J.M. Toguri H.W. Smith 《International Journal of Mineral Processing》1983,11(3):203-219
Bubble size distributions and flotation rates were determined as a function of air flow rate and frother concentration using a specially designed batch flotation cell. This cell permitted the unambiguous determination of the flotation rate from the slurry to the froth.Flotation rate constants were determined for different size classes of silica and galena. The flotation rate constants increased to a maximum and then decreased as air flow rate was increased. This maximum was predicted by a model which considered the effect of bubble size on both the total bubble surface area and the bubble-particle collision efficiency. This work shows that collision efficiency effects, shown to exist in single-bubble/single-particle systems, are also present in flotation systems where many bubbles and particles interact.A second model for hindered flotation is proposed which assumes that the particle-capturing bubble surface differs from the particle-retaining surface. This model predicts a sharp transition from hindered to free flotation. Experimental results are presented which agree well with those derived from the model. 相似文献
16.
17.
针对传统上游法尾矿库堆坝方法的缺陷与不足,提出了改进的上游法堆坝方法,即高浓缩分级尾矿上游法堆坝方法。基于尾矿库堆坝模型试验,以高浓缩尾矿堆存技术为指导,分别进行传统上游法和改进上游法的高浓缩尾矿堆坝模型试验,演绎尾矿库堆坝过程,测试并得出了堆坝过程中滩面尾矿沉积情况、尾矿颗粒分布规律及浸润线变化规律,并采用极限平衡法计算不同堆坝方式下坝体的最小安全系数。结果显示：高浓缩尾矿堆坝使沉积滩颗粒分布均匀,颗粒分级不明显,减少了互层和细泥夹层的出现,改善了坝体内部结构;改进上游法堆坝可以形成有利于排渗防洪的良好沉积滩滩型;稳定性分析结果表明,改进上游法堆坝方法可以使尾矿坝的稳定性提高19%～33%,研究成果可为新建尾矿库工程提供试验技术支撑。 相似文献
18.
《Applied Geochemistry》2003,18(9):1373-1386
The Baccu Locci stream catchment (Sardinia, Italy) is affected by serious As contamination as a consequence of past mining. The presence of both point and widespread sources of contamination (waste-rock dumps and flotation tailings, respectively) strongly affects surface water chemistry, and produces high As concentrations (hundreds of μg l−1) in stream waters. Water chemistry of the Baccu Locci stream changes considerably over a distance of about 10 km as a consequence of various, locally concomitant, processes acting along the stream course: (1) mixing with metal-rich SO4 waters; (2) dissolution/precipitation of metal-bearing phases; (3) mixing with HCO3-dominated lake waters; (4) gypsum dissolution coupled with calcite precipitation; (5) mixing with dilute surface and/or ground waters. In contrast to metals (e.g. Pb, Cu, Zn and Cd), whose dissolved concentrations rapidly decrease downstream of the mined area through (co-)precipitation/adsorption mechanisms, As concentrations tend to gradually increase (up to 0.9 mg l−1) along the stream course as far as the alluvial plain, though significant variations are locally observed. This behaviour is mainly due to the higher mobility of As than metals under the near neutral-oxidative conditions occurring in the Baccu Locci stream waters. Results of a leaching test indicate that part of the As contained in the flotation tailings occurs as As(III), which is more mobile and less strongly sorbed than As(V). The As released to the waters by various mechanisms (i.e. release/desorption from the Fe(III)-hydroxides coatings of silicate grains, oxidation of residual arsenopyrite, decomposition of scorodite) tends to remain in solution and to be transported long distances. As a consequence of the widespread presence of highly As-contaminated flotation tailings all over the medium-lower Baccu Locci stream catchment, long-term As contamination is expected. 相似文献
19.
Antonio M. Álvarez-Valero Reinaldo Sáez Rafael Pérez-López Joaquín Delgado José M. Nieto 《Journal of Geochemical Exploration》2009
The beginning of polymetallic sulphide ore exploitation at Almagrera, Iberian Pyrite Belt, SW Spain, has been dated back to pre-Roman times; mining activity lasted until 2001 when it was definitely halted. The Almagrera sulphide tailings dam was built at the Sotiel–Coronada mine, where Cu, Zn and Pb concentrates were obtained by flotation processes, and sulphide (mainly pyrite) wastes formed. The dam was built as a water-reservoir, on a tectonic fault; its hazard is currently documented by the released wastes after a strong storm in the region, then, its stability is not monitored by the owner. 相似文献
20.
最小孔隙比是确定岩土体的密实程度与孔隙特征的有效物理指标,如何快速有效地确定岩土体的最小孔隙比,可为岩土体的固结与稳定提供可靠参数。多数估算细粗混合材料最小孔隙比的模型参数与细粗粒径比一一对应,导致估算困难。在分析尾矿粒度组成、沉积规律和固结稳定的基础上,以8种不同粗细粒径,7～9种不同细粒含量尾矿为试验对象,拟合得到不同粒组尾矿最小孔隙比分布模型参数的函数关系;基于混合尾矿颗粒的粒组特征,给出了确定参数幂函数关系的指数值。分别采用模型参数要求粒组范围内的其他6组岩土材料和非粒组范围内的3组岩土材料进行验证。结果表明,考虑粒组分类影响下的模型,参数简单,对不同材料的最小孔隙比估算准确率较高,给出的最小孔隙比的分布规律合理,可为岩土工程领域最小孔隙比估算提供可靠的计算方法。 相似文献