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1.
Studies have been made on the separability of clay minerals such as kaolinite, illite and montmorillonite from hematite in dispersant-starch flocculant systems. The grossly different dispersibility of hematite from that of clay minerals aided separation by selective dispersion and flocculation. Moderate success has been achieved with a selectivity index nearing 4.0 (average recovery values around 80%).The studies have been extended to hematite recovery and clay rejection from the slimes of the Barsua iron ore washing plant owned by Rourkela Steel Plant, India. Limited success achieved in the starch selective flocculation method has been attributed to the difficulties associated with fine grain size, clay mineraloty and liberation.The ore exhibits the phenomenon of differential grinding. Hematite-rich coarser particles in the slime can be separated by differential settling in dispersant systems followed by selective flocculation in low-starch systems.  相似文献   

2.
The market requirements for higher-grade concentrates of iron to improve the productivity of the iron and steel industry, has increased the importance of the flotation process with respect to the conventional preconcentration of ore by gravity or magnetic separation. The flotation method most commonly applied is the one that is based on cationic flotation of silica and silicates (reverse flotation), and which is preceded, or not, by desliming or selective flocculation.  相似文献   

3.
The selective flocculation of hematite from silica has been studied from a chemical standpoint. Flocculation was induced in a stirred vessel under various reagent dosages, flocculant, dispersant and electrolyte, various pHs and slurry densities. The effectiveness of a given treatment was examined by the resulting grade of material reaching the outlet of a setting tube compared with the quantity.It was confirmed that selective flocculation is more favourable with more highly charged anionic polyacrylamide flocculants and with higher molecular weight. The process appears insensitive to dosage of flocculant in the range 1.5 to 10 ppm, but slurry densities must be kept low.Under such conditions the use of redispersion produced little gain in grade of hematite fraction but considerable loss in recovery.  相似文献   

4.
This investigation has shown that quartz can be activated for polyacrylic acid adsorption by hydrolyzing metal cations, similar to activation in flotation. Detailed experiments on activation phenomena with ferric ions have been performed. The flocculation of activated quartz can be prevented by suitable additions of disodium EDTA, sodium hexametaphosphate or potassium fluoride. Selective flocculation of hematite with polyacrylic acid from a hematite/quartz mixture can be achieved in the pH range 3 to 9, but the process is not selective in the presence of ferric ions. Suitable additions of EDTA or KF are particularly successful in preventing quartz activation by ferric ions and the facilitating selective flocculation of hematite in artificial mixtures of quartz and hematite.  相似文献   

5.
Experiments have shown that it is possible to obtain a concentrate containing 65% iron, 1.8% alumina and 1.4% silica with an iron recovery of 80% from the tailings of Barsuan iron ore plant containing 52.5% iron, 7.4% alumina and 7.8% silica through selective flocculation employing starch. Key to such success lies in the manner in which the flocculant is desired from the parent starch. Barsuan deposit being a limiting case of typical fine-grained high-alumina iron ores, the results open up technical possibilities of better utilization of such deposits.  相似文献   

6.
The possibility was investigated of carrying out selective flocculation in the model set smithsonite-dolomite using polymers containing nitrogen atoms, which should interact selectively with zinc minerals.A high activity of flocculants in relation to smithsonite and a low activity towards dolomite was observed. However, the activation of the dolomite surface by Zn2+ ions was determined whereby the selective flocculation was not observed in the mixture of smithsonite and dolomite.  相似文献   

7.
Having previously established a system of hematite and silica which can be separated effectively using long-chain polyacrylamide flocculants (Part 1) a stirred tank system was chosen to enable physical variables of flocculant concentration, impeller speed, time of flocculation, slurry concentration, ratio of hematite to quartz in the feed and particle size distribution to be studied.It was concluded that the time of flocculation allowed should be kept short and that there is an optimum of impeller speed though not a sharp one. Slurry concentration must be kept to 1% w/w to prevent serious performance deterioration. A clear optimum flocculant concentration was not found under present circumstances though very low concentrations (< 1 ppm) gave poor results while high concentrations gave no improvement on the results at about 2 ppm.Comparison between an impeller and a propeller of the same diameter and location in the tank pointed to the possibility of critical agitation configurations and the need for caution in scaling up results.The grade of material settling from a selective aggregation process is heavily dependent on the particle size distributions of the mineral species. Larger flocculated minerals produce richer flocs.  相似文献   

8.
In the present study, the removal of dissolved and colloidal Cd, Co, Cu, Ni and Zn in Arvand River water during estuarine mixing with the Persian Gulf water is investigated. The flocculation process was investigated for a series of mixtures with salinities ranging from 0.48 to 30.3^. The flocculation rates were indicative of the non-conservative behavior of studied metals during estuarine mixing. Rapid flocculation in the low salinity regimes was observed. The order of the final flocculation rate of metals in the river water was as follows: Co (91.2%)> Cd (86.9%)> Zn (83%)> Cu (75.2%)> Ni (74.3%). Salinity, pH, EC and dissolved oxygen do not govern the flocculation of metals during estuarine mixing. The results of the present investigation show that estuarine processes can be considered as an effective mechanism in self purification of colloidal metals that are anthropogenically introduced into the fresh water ecosystem.  相似文献   

9.
Basically speaking, flocculation and coagulation should be theoretically treated as a many-body problem. However, such potential energy theories of coagulation as the DLVO theory have been developed as a two-body problem, i.e., interaction between two plates or two particles in an infinite medium. The concept volume fraction of the constituent particles in the floc, i.e., voidage fraction in the floc is excluded from these theories and, therefore, the traditional theories are not applicable to the phenomenon of “pelleting flocculation”.In an effort to formulate a theory of flocculation that leads to pellet-like flocs, three possible mechanisms of flocculation process are involved, i.e., (1) perikinetic flocculation, (2) orthokinetic flocculation, and (3) an additional process of mechanical syneresis. A few hypotheses are also presented, which may become the prelude to a subsequent flocculation theory.  相似文献   

10.
The process of pelleting flocculation, a further development of classical flocculation technology, is defined as a formation of wet pellets directly in a liquid medium. Apart from well described mechanisms of flocculation like perikinetic and orthokinetic flocculation, the mechanism responsible for the formation of dense agglomerates is the mechanical syneresis guaranteed by the appropriate reactor form. Upon the two established models in the literature: the series system and the parallel system, experiments were performed to simulate a layer-by-layer particle deposition on the so-called “mother seeds” conforming to the parallel system.The present paper deals with the results originating from laboratory scale experiments with model sludge, kaolin suspension. The layering process was conducted in the presence of different cationic flocculants and the resulting relationships with respect to their nature and to the applied energy level have been assessed. The achieved agglomerates exhibit an “onion like” structure with densities up to 1.42 g/cm3 and solid matter content up to 48% after gravity dewatering. Thus generated sludge agglomerates reveal the optimisation potential for sludge treatment manifested by improved characteristics achieved during the conditioning.  相似文献   

11.
Polyacrylate and hydroxamate flocculants are commonly used to aid solid–liquid separation of bauxite residue from pregnant liquor in the Bayer process. This study presents the direct examination of the bauxite residue flocculation with polyacrylate and hydroxamate flocculants, using the focussed beam reflectance measurement (FBRM) probe to monitor aggregate dimensions.The key difference between polyacrylate and hydroxamate flocculation was found to be the way the aggregates developed post-shear, with hydroxamate flocculation exhibiting a greater degree of post-shear flocculation. Polyacrylate aggregates were found to be more dense and shear resistant, while the hydroxamate aggregates exhibited greater fines capture and lower solids in the supernatant. The solids remaining in the supernatant after flocculation were found to differ for each flocculant, with the polyacrylate system having relatively more coarse particles within the solid and the hydroxamate system being relatively finer and more iron rich. The observed results are discussed in terms of the different way in which each polymer is considered to adsorb onto the residue material.  相似文献   

12.
The Snake River iron ore deposit, in the northern Yukon, Canada, is an enormous, potentially valuable natural resource. Conservative estimates indicate that the deposit contains some thirty thousand million tons of ore. Unfortunately the chemical quality of the mine-run ore falls significantly below established industrial specifications, in particular the phosphorus content is not acceptable. Previous mineralogical examination of the deposit has indicated that the gangue constituents are finely disseminated throughout the ore.An outline is given for the selective agglomeration of the ore to concentrate the phosphorus minerals during grinding. The ground ore is then further treated to agglomerate selectively the iron fraction, which can then be separated from the remaining gangue constituents by differential settling. Successful beneficiation has been achieved on both the crude Snake River ore and a jig concentrate, with some concentrates assaying 69.0% Fe and <0.03% P (iron-ore specification is 0.07% P max.). The effects of various parameters on efficiency of separation are discussed.  相似文献   

13.
To interpret the leaching rules, select suitable treatment methods, or optimize the treatment process of refractory gold ores, an in-depth analysis of ore characteristics using ore mineralogy is required. In this study, the mineralogical characteristics of a low-grade refractory gold ore were analyzed by a variety of analytical techniques and methods. The ore composition was obtained by chemical analysis, and the main minerals include gold, pyrite, arsenopyrite, feldspar, mica, and quartz. Gold exists in the form of sub-microscopic gold with a particle size of fewer than 1.7 μm, of which 56.90 % is encapsulated gold, 16.97 % is semi-coated gold, and 26.13 % is fractured gold. The content, classification, shape, grain distribution, and occurrence state of the main minerals in the gold ore were obtained by microscopic observation and statistical analysis. Based on the results, the leaching rules of the gold ore were predicted, and suggestions for optimizing the pretreatment process were put forward. These results can accurately guide the pretreatment and leaching process of the gold ore and lay a foundation for the effective utilization of comparable gold ores.  相似文献   

14.
综合信息矿产预测计算机系统   总被引：3，自引：0，他引：3  
以综合信息矿产预测理论、方法为指导,在对比综合信息矿产预测方法与ＧＩＳ系统结构基础上,以ＧＩＳ为平台,开发本计算机系统。核壳式结构是本系统开发的理论基础,进而提出本系统的工作原理、总体设计和一系列研究方法;也介绍了矿产预测计算机系统的软件流程及编程原理  相似文献   

15.
内蒙古拜仁达坝铅-锌-银矿床:元素分带及其成因   总被引：2，自引：0，他引：2  
内蒙中东部拜仁达坝矿床是一个以石炭纪石英闪长岩及锡林浩特杂岩为赋矿围岩的断裂充填型热液脉状铅-锌-银多金属矿床。矿床分东西两个矿段,拜东矿区1号矿体及拜西矿区3号矿体是矿床的主要矿体。矿体沿着走向方向具有明显的矿化分带特征,锌-铜矿石、锌矿石及铅-锌-银矿石依次从矿化中心向外侧产出。代表性矿体拜东矿区1号矿体的块段金属量、平均品位及元素比值由西向东沿着走向方向显示出明显而系统的变化规律。锌的块段金属量由西向东逐渐减少,铅和银的矿段金属量则先增加后下降;锌的块段平均品位由西向东逐渐降低,铅和银的块段平均品位则先上升随后下降;Ag/Pb值先上升随后下降,Ag/Zn和Pb/Zn值则逐渐上升。这种矿化的分带性可能是成矿热液在中偏高温向低温演化的过程中,沿着矿体的走向方向从矿化中心向外侧运移,在矿体不同位置有选择地将成矿物质卸载的结果。而成矿热液在断裂系统内与不同比例大气水的混合则可能是成矿系统内温度梯度形成的重要原因。矿床中不同位置的矿物组合记录了成矿热液中硫逸度由高向低,pH值由低向高的演化过程。拜仁达坝矿床与邻近的维拉斯托矿床组成了一个由温度场控制的具有明显矿化分带现象的低硫化热液脉状多金属成矿系统。  相似文献   

16.
白云生 《矿床地质》1983,2(1):58-65
我们在某新第三系盆地进行以铀为主,兼顾其它有用矿产的勘探工作中,落实了一个大型的含铀锗矿床。经工艺流程试验,锗铀均能综合利用。为了更好地认识、研究和寻找此类矿床,笔者特将该矿床的成矿特征及对其肤浅认识简介于下,以供读者和从事此类矿床的研究者们参考。  相似文献   

17.
The product of the mining industry (ore) is considered to be the raw material for the metal industry. The destination policy of the raw materials of iron mine is highly dependent on the class of iron ores. Thus, regular monitoring of iron ore class is the urgent need at the mine for accurately assigning the destination policy of raw materials. In most of the iron ore mines, decisions on ore class are made based on either visual inspection by the geologist or laboratory analyses of the ores. This process of ore class estimation is time consuming and also challenging for continuous monitoring. Thus, the present study attempts to develop an online vision-based technology for classification of iron ores. A laboratory-scale transportation system is designed using conveyor belt for online image acquisition. A multiclass support vector machine (SVM) model was developed to classify the iron ores. A total of 2200 images were captured for developing the ore classification model. A set of 18 features (9-histogram-based colour features in red, green and blue (RGB) colour space and 9-texture features based on intensity (I) component of hue, saturation and intensity (HSI) colour space) were extracted from each image. The performance of the SVM model was evaluated using four confusion matrix parameters (sensitivity, accuracy, misclassification and specificity). The SVM model performance was also compared with the other methods like K-nearest neighbour, classification discriminant, Naïve Bayes, classification tree and probabilistic neural network. It was observed that the SVM classification model performs better than the other classification methods.  相似文献   

18.
成矿过程中由流体混合而导致金属沉淀的研究   总被引：19，自引：0，他引：19  
对成矿流体的研究已成为当前矿床学和地球化学领域重要的前沿课题，其主要进展之一就是确认由不同性质流体的混合导致金属沉淀是矿石形成的重要方式。从流体混合过程的现代自然现象研究出发，以近年来国内外最近研究成果为基础，以岩浆水与大气降水的混合为重点，综述了成矿过程中几种主要的导致金属沉淀的流体混合作用，并对其主要机理─—冷却、稀释、酸碱度改变和氧化还原反应──进行了初步讨论。  相似文献   

19.
根据官地银金矿中锰矿物的共生组合情况，引用Al（NO3）3溶液作碳酸锰矿物的选择性溶剂，H2SO4-KF-HF混合溶液作水锰矿、褐锰矿的选择性溶剂，于滤渣中测定软锰矿（包括少量硅酸锰矿物）。实验表明，所引方法适用于官地银金矿区锰矿物的相态分离，所得结果与外检结果一致，满足了矿床划带的实际需要。  相似文献   

20.
利用不同性质颗粒在流化状态下可实现自然水力分级的特征,在流化床反应器中沿水流方向实现了多级速度梯度的建立。在研究流化床混凝反应器的混凝动力学特征基础上,探讨了以800 μm和1 200 μm树脂颗粒为固相的多级速度梯度流化床（MGF）的速度梯度分布特征、混凝效率和絮体形态特征,并与以1 200 μm树脂颗粒为固相的单级速度梯度流化床（SGF）进行了对比研究。结果表明：与单级速度梯度相比,多级速度梯度可为胶体或微颗粒的高效碰撞和絮体再增长创造更适宜的环境,有助于形成尺寸更大、密度更大的絮体,提高了絮体的可沉降性;MGF在处理人工配置的高岭土悬浊液和分散红染料废水时,混凝效率比SGF分别提高了2%～4%和7%～20%。  相似文献   

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