Treatment Of Slimes Research Articles

A water model study on mixing behaviour in a Kaldo furnace using acid–base neutralization decolourization method combined with RGB-based image analysis

Mixing time is usually used as an important parameter for quantifying the mixing performance of multiphase flow in a metallurgical bath. However, the topic of the mixing time of a Kaldo furnace for copper anode slime treatment has received little attention from scholars to date; this concept is important for guiding the optimization of high-efficiency smelting in the Kaldo furnace. In the present work, the mixing behaviour of gas-liquid two-phase flow in a Kaldo furnace was simulated using a scaled-down 1:4.5 water model fabricated from transparent acrylic plastic. A visualization technique and a quantitative characterization method for mixing performance in the Kaldo furnace—acid-base neutralization decolourization combined with RGB-based image analysis—were innovatively proposed. This approach can not only determine the global mixing level η¯(t) and track the frequency distribution of the local mixing performance ξk(t) of the fluid region during the mixing process but also quantify the mixing time. In addition, based on the proposed method and by using dimensional analysis, the effects of operating parameters (such as the gas flow rate Q, injection lance height h, rotation speed ω, liquid volume fraction φ, inclination angle θ, and liquid viscosity μl) on the mixing time of gas-liquid two-phase flow in the molten bath were discussed. On this basis, the empirical equation of the mixing time as a function of h, ω, φ, the modified Froude number (Fr'), μl and θ was established as the first quantitative relationship of the mixing time for the Kaldo furnace.

Acid treatment as a beneficiation method for phosphorite waste of Kyzylkum phosphorite plant

This article addresses matters relating to the recycling of waste from the Kyzylkum phosphorite plant in the form of phosphorite slimes, the mass of which exceeds 3 million tons at present. The treatment of slime with sulfuric acid having the concentrations from 2 g/l to 40 g/l made it possible to determine the most optimal concentrations (up to 10 g/l), at which the salts of alkali and alkaline earth metals, uranium and other elements are separated. This method permits obtaining a richer fraction of the useful component, phosphorus(V) oxide (up to 19.1%). At the same time, the pH value of the medium remains in the neutral range. Mass spectroscopy showed that such treatment with sulfuric acid having the concentrations up to 10 g/l allows selectively dissolving carbonates without decomposing phosphates. IR spectra of phosphorite slime after acid treatment do not contain absorption bands characteristic of CO32– groups. In accordance with the obtained results, a low-cost technological scheme for the phosphorite slime utilization was developed, followed by its introduction into the production process without violating the main technological regulations. The enriched slime fraction corresponds in quality to the burdened phosphorite ore and can be used as an additional product.

Evaluation of the Pullout Behavior of Pre-Bored Piles Embedded in Rock.

The subject of this study is dry process caisson tube method cofferdam (hereinafter called C.T cofferdam). This C.T cofferdam is designed to use the skin friction of the drilled shaft embedded into the rock for stability of buoyancy. A pre-bored pile embedded in the bedrock was pulled out due to the buoyancy of the C.T cofferdam at the pier (hereinafter called P) 2 of the OO bridges under construction, to which this was applied. In this study, in order to solve this problem, the adhesion force applied with the concept of skin friction and the pre-bored pile of drilled shaft according to domestic and foreign design standards were identified; the on-site pull-out load test was used to calculate the pull-out force; and the skin friction of the drilled shaft and pre-bored pile embedded into the bedrock were compared and analyzed. In addition, the pull-out behavior of the pre-bored pile embedded in the bedrock was analyzed through numerical analysis. The adhesion strength tested in the lab was 881 kN for air curing of concrete and 542 kN for water curing of concrete, and the on-site pull-out test result was 399.7 kN. As a result of the numerical analysis, the material properties of the grout considering the site conditions used revealed that the displacement of the entire structure exceeded the allowable limit and was unstable. This appears to have lowered the adhesion strength due to construction issues such as ground complexity and both seawater and slime treatment, which were not expected at the time of design.

Sustainable chemical reaction-free vacuum separation process to extract selenium from high-value-added hazardous selenium sludge

High-value-added hazardous selenium sludge extracted from copper anode slime may cause serious selenium contamination and potential threats to human health if improperly treated. In this study, a sustainable chemical reaction-free vacuum separation process was used to extract selenium and recycle valuable metals from selenium sludge. The process comprises low-pressure dehydration and Se extraction by vacuum distillation. The laboratory-scale results indicate that 90.76% of selenium was extracted from volatiles at a purity of 98.68% under the optimum distillation conditions of 693 K, 90 min and 30–50 Pa. Ag and Au were enriched to 28004 g/t and 1226 g/t in residues from 2560 g/t and 112 g/t, respectively, in raw materials, representing increases of 10.4 and 10.25 times. On this basis, a low-pressure melting-vacuum distillation process and equipment with an annual selenium sludge disposal capacity of 500 metric tons were developed for industrial production. The continuous production data show that the purity of the extracted selenium always exceeded 98.0%, the direct yield ratio of selenium exceeded 96.5%, and the consumption was only 1150 kW h electricity per ton of selenium ingot output. Additionally, Ag and Au were enriched by over 11 times in the residue. The discharged water evaporated, and residues were returned to the comprehensive copper anode slime treatment process for the further valuable metal extraction. Compared with chemical processes, the proposed technology consumes fewer resources and reduces the environmental impacts, resulting in better economic and sustainability assessment results. The proposed process meets the demand for cleaner production within the selenium metallurgical industry.

Research on Separation Process of Coarse Slime of Hydrocyclone Based on Computer Information Technology

The terminal equipment of the slime treatment system needs to realize that the slime water can be directly recycled or meet the conditions of direct discharge. The slime selection process has two main parts: first, the selection process and second, the product dehydration process. The slime recovery and recovery process has two main parts. The first is coarse slime recovery and dehydration equipment and the second is fine slime recovery and dehydration equipment. The above factors are the necessary conditions to realize the closed circuit of slime water. In these mitigations, the use of computers to complete their work can effectively increase production and this article studies them.

煤泥处理新技术

煤泥处理新技术

Theory of Copper-Electrolyte Slimes Decoppering in the Presence of Hydrogen Peroxide

The problem of copper leaching from copper-electrolyte slimes is discussed. To intensify the long and costly process, it is proposed to use a leaching system containing sulfuric acid and hydrogen peroxide as an oxidizing agent. The chemical transformations possible variants at the treatment of slime under the specified conditions and the thermodynamic parameters of the predicted reactions are considered. Solution composition effect on the copper dissolution rate at room temperature was studied in the presence of hydrogen peroxide using the rotating disc technique. It is found that dissolution rate constant at using hydrogen peroxide slightly inferior to dissolution rate constant under autoclaved conditions in an oxygen atmosphere.

Investigation of flocculation efficiency in treatment of wet gas treatment slime of ferroalloys production

The object of research is the process of wastewater treatment from suspended solids, formed as a result of wet gas treatment of the exhaust gases of ferroalloys production shop. As a result of the audit, it is revealed that the flocculation of slimes in the current water circulation cycle scheme does not occur with due efficiency, since the dosing of the flocculant is made at one point in the slime water pipe, without adjusting its dose when the slime concentration, dispersion and chemical composition change. It is found that the gas treatment slimes have a high content of dissolved salts up to 26 g/l, a variable chemical composition and pH of 8 to 10, as well as a high proportion of fine particles of less than 40 μm in size. It is established that the peculiarities of mixing slimes with flocculant play an important role in flocculation. For effective treatment of slimes and elimination of these drawbacks, it is suggested to introduce flocculant not once but in two portions 35–40 % and 60–65 %, respectively, with a mixing time of up to 30 seconds of the first dose and about 10 seconds of the second dose. The possibilities of effective treatment of slime waters of wet gas treatment up to 0.35 g/l are established using sedimentation centrifugal plants. It is recommended to take the slime intake directly at the outlet from the ferrosilicon production shop with the solids phase fraction with a size larger than 40 μm in excess of 80 % and a concentration of up to 10 g/l.

Investigation of the treatment efficiency of fine-dispersed slime of a water rotation cycle of a metallurgical enterprise

The features of the water rotation cycle and the slime treatment system of the oxygen-converter shop of metallurgical production are investigated. During the audit, it is revealed that the concentration of suspended solids in the water cycle system varies in time up to 500 g/l for the condensed slime and up to 85 g/l in the pre-clarified water. It is established that the slimes of the metallurgical enterprise contain a finely dispersed solids fraction in the slime up to 93 % of a size of less than 20 μm and the residues of a cationic flocculant that impede effective treatment of the slime in the sedimentation tanks. This leads to the following drawbacks: a decrease in the slime treatment efficiency, removal of the fine fraction of solids together with clarified water of radial thickeners, regular replenishment of clean water, discharge of part of the flow into the slime collector. It is proposed to install an additional treatment module and use a more efficient anionic flocculant. It is recommended to monitor the efficiency of treatment and dosing of the flocculant depending on the solids concentration in the slime by continuous sampling and testing of slime flocculation. It is established that effective treatment up to 99 % can be achieved on the treatment module using anionic flocculant, thin-layer sedimentation tanks and sedimentation horizontal screw centrifuges.

Weste products of steel galvanizing processes for obtaining technology of colored glazes

The subject of this research is glass-forming compounds pegmatite-slag of thermal pover plants-waste products of galvanizing processes based on frits. The subject of this research is colored low-melt glazes. The objective of the work is elaboration of compounds and technology obtaining colored glazes using waste products of steel galvanizing processes. Up-to-date methods of investigation (X-ray phase analysis, differential thermal analysis, flame photometry and optical electroscopy) have been used in this work. Peculiarities of the formation of slimes of steel parts galvanizing and their properties have been investigated. The processes of gas formation in the process of thermal treatment of slimes have been studied in the range of temperatures 293…1773 K. Regularities of crystallization of coloring crystal phases α-Fe 2 o 3 , ZnO •Fe 2 o 3 and Feo•Fe 2 o 3 that ensure obtaining colored glazes have been established. Technology of obtaining low-melt glazes of brown and cherry-brown colors based on low-melt frit without adding additional ceramic pigments with firing temperature 1343…1373 K has been elaborated. It was established, that with the increase of slime content from 10 to 30 weight % in the composition of glazes the color of coating changes from brown to cherry-brown and the purity of color increases from 31 % to 47 %. The obtained compositions of such glazes were successfully tested under the manufacturing conditions and confirmed the possibility of producing decorative oven ceramic tiles with improved decorative and maintenance properties.

Pigments based on thermally treated iron-containing slimes

The effect exerted by chemical and phase composition on the color characteristics of the products of a heat treatment of slime obtained at purification of model wastewaters containing prescribed amount of zinc(II), nickel(II), copper(II), and chromium(III) compounds using ferroferrihydrosol was studied. The dependence of pigment properties of the products of the heat treatment of slimes on the concentration of metal compounds in them was determined.

Mechanism and products of thermal treatment of slimes obtained at treatment of wastewaters using ferroferrihydrosol

Phase, dispersion, and chemical compositions of the products of thermal treatment of slimes obtained by treatment of model solutions and industrial wastewaters from electrochemical production using ferroferrihydrosol were studied. The dependence of the phase composition of the slime treatment products as influenced by the content and ratio of heavy metals in wastewaters was evaluated.

日立工場における最近の操業（日鉱金属（株））

The Hitachi Smelter & Refinery changed its name to the Hitachi Refinery and started operation with establishing the Nippon Mining & Metals in November in 1992.After the shut down of the Smelting Division in 1976, the Hitachi Refinery, mainly operating copper tank house and anode slime treatment section, established the development and production systems for new materials and valuable materials with joining various divisions of groups of our company.In the anode slime treatment section in the Saganoseki Smelter & Refinery was combined with the Hitachi Refinery in 1981.In result, the inventory of silver & gold and labor costs were reduced.At the tank house in 1989, a pitch changeable hunger was developed and the pitch of anode to anode was reduced from 110 mm to 100mm, resulting in increasing in the monthly capacity of cathode from 10, 000t/M to 11, 000t/M and reducing the electrical power consumption.In September in 1988, the Sb-removing process (NCR-process) using chelating resin was installed.This process highly contributes the stability of tank house operation.The reverberatory furnace, installed in 1978, for treating industrial waste is operating in good condition; furthermore a waste oil treatment plant was installed in April, 1993.Recycling Division is now planning to expand and is contributing to the maintenance of the ecological balance and environmental cleanliness of the earth.

The treatment of copper refinery anode slimes

There are numerous viable approaches to the treatment of anode slimes from electrolytic copper refining. Of particular interest in the treatment of slimes are the behavior and recovery of selenium. The understanding of the process chemistry involved in the treatment of anode slimes should be aided considerably by recent work on the formation and characterization of slimes. Most promising is a direct furnace treatment of decopperized and detellurized slimes, in which selenium is volatilized as the dioxide, impurities such as lead are slagged off, and a high-quality dore metal is obtained.

The wet chlorination of electrolytic refinery slimes

This article briefly describes the classical processes of dore furnacing and refining and identifies the major problems and costs associated with these methods. The process chemistry of the wet chlorination of slimes is then described, followed by an examination of the various unit processes employed to recover the metal values from slimes. Finally, a conceptual treatment of slimes is presented and compared to conventional processes.

タングステンのスライム選鉱について

タングステンのスライム選鉱について

日立製錬所における最近の銅製錬

Hitachi Smelter & Refinery of Nippon Milling Co., Ltd. has greatly devel oped its technology and has increased its copper production capacity.Oxygen Smelting Process was applied in 1958, and concentrates were charged into converters and blister copper was directly obtained by using oxygen enriched air. In 1972, the Oxygen Smeiting Process was taken over by Flash Smelting Process, With a monthly productlon capacity of 7, 000 tons of copper from concentrates.Oxygen ennchment was also applied to the flash furllace operation in which the high temperature air was supplied by hot stoves.In addition, the monthly refining capacity rcached 16, 000 tons of copper by constructing a new tank house with a monthly capaclty of 10, 000 tons of electroiytlc copper. The new tank house is equipped with only one over-head crarle, as a result of instaliing highly developed handling machilles and a special double-hook system, That can simultaneously crop both anodes and cathodes.New slime treatment plant was also constructed, The technology of The Ferric Leaching Process was developed and a high efficiency of copper removal from anode slime was realized.Owing to the econornlcal suppression, the smelting division has been shut down since September in 1976. The anodes have been transported to Hitachi tallk house from Saganoseki Smeiter.

黒鉱選鉱操業の概況と問題点

“Kuroko” so called Black ore is a kind of complex polymetallic sulphide ore, the texture of which is very intimately associated with sulphide minerals such as copper, lead, zinc, iron etc. Numeraous deposits of the ore, which are widely distributed in the north-eastern district of Japan, are actually being mined and their output are concentrated by differential flotation processes. But, because of complexities in the nature of the ores, namely the variety of mineral content and mineral composition, fineness of mineralogical texture and tendency to oxidize easily, it is considerably difficult to obtain satisfactory separation of the costituent minerals.This article describes a general survey and some technical problems on the mill operations of the ores. The problems which were pointed out and reviewed by the author are as follows;(1) ore characteristics and processes of separation.(2) liberation of individual minerals.(3) processes for treatment of slime.(4) oxidation of ores.(5) flotation reagents used and elimination of their residual effects.(6) variation in grades and properties of feed ores and overall control of mill operation.

銅電解アノードスライム湿式処理法の研究とその工業化

銅電解アノードスライム湿式処理法の研究とその工業化