Fine Slime Research Articles

Review of Reducing Entrainment of High Ash Fine Slime to Concentrate in Flotation Process

Review of Reducing Entrainment of High Ash Fine Slime to Concentrate in Flotation Process

Magnetic seeding sedimentation (MSS) of coal slimes

Magnetic seeding sedimentation (MSS), i.e. adding magnetic seeds and pre-magnetization for sedimentation, is a technique especially for sedimentation of fine slimes, improving the sedimentation performance by introducing the magnetic interactions between particles in a suspension and enlarging the apparent size of the fine particles. The fine coal slimes with a size of 66.68%-38μm were investigated by the MSS. Sedimentation tests were conducted, and some measurements, such as laser size analysis, magnetic susceptibility by vibrating sample magnetometer (VSM), were also applied in order to probe the mechanism of the MSS. Based on the tests, measurements and calculations it was demonstrated that the sedimentation of coal slimes increased with the additions of the magnetic seeds, and in the presence of the polyacrylamide, and also there appeared a relatively large apparent size of slimes after additions of magnetic seeds and/or polyacrylamide. So, the reason for the influence of MSS lies in fact that the presence of the polyacrylamide intensified the adsorption of magnetic seeds on the coal particles and the coverage of the magnetic seeds on the coal surface from 0.2% wt. to1.3% wt., resulting in increased magnetic susceptibility of coal particles from 9.13×10-9m3/kg to 22.17×10-9m3/kg and thus a low magnetic field strength of pre-magnetization needed for the magnetic agglomeration to happen among the coal particles (the threshold of magnetic field strength for agglomeration) from 602mT to 24mT prior to proper sedimentation.

Effect of fine slime on the choice of columbium ore pretreatment flowsheets

The article presents studies of slime formation in processing of Vishnevogorsk columbium ore. The slime formation criterion is assumed as the presence of size grades less than 50 and 5 µm estimated from modern laser granulometer data. The optimal methods and equipment for grinding are chosen depending on rate of slime formation in final products. The studies use centrifugal and rod mills. The rod mill assures the lowest rate of slime formation. Based on the experimental results, the columbium ore pretreatment flowsheet and special ore disintegration methods have been selected. The flowsheet uses crushing machines ensuring the highest rate selectivity—inertia cone crusher and the lowest rate slime formation during milling—rod mill.

Comparison of Combination of Flotation-Magnetic-Gravity Separation Process with Bluk Flotation for Recovering Fine Tin Slime

A comparative analysis of the combination of flotation-magnetic -gravity separation with bulk-floatation process for recovering fine tin slime was carried out in a mineral processing plant. Compared to the bulk floatation process, the flotation-magnetic-gravity separation process resulted in a higher recovery of tin and showed advantages of small consumption of reagents and electric power, stable production index and easy operation.

Lower Ash Experimental Study on New Slime Separator

The flotation is the effective method to fine coal separation, but the cost is higher and flotation reagents pollute circulating water system. In this paper, the JiuLiShan coarse coal slim was classified, the interception of 0.25 mm was collected, fine coal float-and sink test was carried out. For the-0.25mm coarse slime, compare the flotation, conventional coarse coal slime separation and new slime separator separation, the results show: underflow ash increased by 12.4%;the new slime separator is suitable for the 0.25 mm granularity fine coal slime, can be applied to lower fine slime ash, raising cleaned coal yield.

The Sedimentation Experiment of the Fine White Slime Water

There are a lot of white ore in Jixi Qingshan coal mine. Argillization of this ore is very terrible. This ore quickly turns to fine white slime in water and forms the stable suspending liquid. It leads that slime water form sediment is very terrible. This paper analyzed and researched the characters of the fine white slime water. The experiment results showed that the combined applied effect of MgCl2 and NPAM can enhance form sediment effect. The sample is the coal sample used in Jixi Qing Shan coal mine, which contains lots of white ore and is dipped in water for observation. This ore quickly turns to fine white slime in water, superfine, forming the stable suspending liquid. This suspending liquid become sedimentation in the natural placement for several days, which seriously effect the normal operation of the system of the manufacturing part of coal cleaning. This research on the sedimentation experiment of the fine white slime water will be introduced in this thesis.

Efficiently Utilizing a Low Grade and Complex Copper Ore by Flotation

Based on the analysis of the properties of the copper ore from Jinggu area in Yunnan province, a suitable technical route was presented for processing of eligible copper concentrate and the main factors i.e. grinding fineness, Na2S dosage and collector dosage, affecting the quality of roughing concentration was investigated. On this basis, a close-circuit flotation test scheme was preceded, which obtained a high quality copper concentrate with Cu grade of 16.08%, copper recovery of 58.52%. The recovery of copper concentrate is much lower than the Cu recovery of roughing concentrate from the condition experiments. This may be contributed to the fact that fine slime carried by middling worsens the separation of copper minerals and gangues. The Mo was enriched in concentrate, which is significantly considered to recovery in further work.

Impact of Pre-Desliming on Flotation of Low-Grade Zinc Oxide Ore from Lanping

Zinc oxide ore from Lanping contained large amount of fine slime which badly deteriorated flotation performance, and it complexly intergrowed with plenty of alkaline gangues with calcium and magnesium. In order to investigate the impact of pre-desliming on flotation, experiments of direct flotation and pre-desliming flotation were carried out in the work. Finally, a zinc recovery of 88.73% with a Zn grade of 13.93% was obtained in direct flotation test, and a higher zinc recovery of 95.25% with a Zn grade of 13.56% was achieved by pre-desliming flotation. Pre-desliming flotation test was superior to direct flotation test, because of an increase of nearly 7% in zinc recovery under the condition of similar Zn grade. At the same time, dosage of sulfurization agent used in pre-desliming flotation was lower by 46.67% than that in direct flotation, which obviously improved the availability of sulfurization agent. So both product index and economic benefit were enhanced after pre-desliming.

Studies on Regulator Experiment of a High-to-Float High-Ash Fine Coal

Aim at high-to-float high-ash fine coal with large content of granules, in order to reduce pollution of carried fine slime to quality of concentrate coal, soluble glass, sodium hexametaphosphate and cornstarch these three kinds of regulators were choosen to carry out flotation reducing ash experiment. Result showed that, cause of poor selectivity of fine coal is mainly small quality, big surface area and the poor dispersion of fine coal. When sodium hexametaphosphate dosage is 1500g/t, the kerosene dosage is 370g/t, the foam beater GF dosage is 150g/t, production rate of concentrate coal is 57.69%，and ash content of concentrate coal is 12.04%. Under the same condition, separation index of sodium hexametaphosphate as regulator is superior to cornstarch and soluble glass.

Improvement in Flotation and Filterability of Fine Coal Slime by Selective Flocculation

The results are presented for the experiment on flotation of hard-to-float high-ash coals and filterability of fine coal slime by the method of selective flocculation.

Turbulent Transport Effect on Hydrocyclone Performance

To date, the hydrocyclone has played an important role in producing classified or concentrated materials and in removing harmful or hazardous substances. The material behavior is dominated not only by the centrifugal force and the mean fluid velocity but also by the structure of turbulence in the hydrocyclone. In this paper the structure of turbulence has been evaluated first by analyzing observed turbulent characteristics and then, the effect of turbulence on the separation performance has been numerically evaluated taking into account the propagation of turbulent energy by diffusive mixing. The results indicate that the separation performance is deteriorated as the intensity of turbulence is increased in the hydrocyclone. In order to improve the separation performance two types of turbulence-free cyclone-like separators, called Minoclone and Staticlone, have been developed, which have been successfully applied to classifying fine particles. Finally, the Staticlone has been applied to remove metallic pollutants from fine slimes. Consequently, it has been proved that the turbulence-free separator can play an excellent role in processing of fine slimes compared with a conventional hydrocyclone.

Potentialities for beneficiation of rare metal ores using high magnetic fields

The present paper deals with the possibilities for beneficiation of rare metal ores, for example wolfram containing, using magnetohydrostatic separation and high-gradient magnetic filtration. The results of magnetic separation of low grade wolfram ore and of fine slimes are demonstrated.