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Bacterial leaching of Pb -metallurgical wastes  [PDF]
P. Fecko,I. Janakova,E. Pertile,E. Kulova
Metalurgija , 2011,
Abstract: The aim of this paper is verification of application of bacterial leaching and calcination to recover heavy metals from metallurgical wastes - matte from metallurgical plant Kovohute Pribram. For bacterial leaching a pure bacterial culture of Acidithiobacillus ferrooxidans was used. For a verification test an original sample of matte and matte from 2004 year were used. This paper further shows changes in the samples after bacterial leaching and after calcination. The paper results imply that the samples in question may be used as pigments.
Leaching and Stabilization of Heavy Metal in the Fly Ash of Medical Wastes
医疗垃圾焚烧飞灰的重金属浸出特性及其稳定化处理研究

TAN Zhong-xin,LIAO Hua-yong,XIE Jian-jun,WANG Xiao-bo,LI Hai-bing,ZHAO Zeng-li,
谭中欣
,廖华勇,谢建军,王小波,李海滨,赵增立

环境科学 , 2008,
Abstract: Through the experiments of leaching and melting on the fly ash of medical wastes, the influence of leaching time, L/S, pH and grain size on the leaching characteristics of heavy metal and the effect of melting on the stabilization of fly ash are studied. Results show that, following the leaching time extending, the leaching concentrations of heavy metals and lixiviate toxicity of heavy metals increase in the fly ash. When the ratio of liquid and solid add, the leaching concentrations of heavy metals obviously become big, and the Cd's leaching concentration is the biggest, when the ratio of liquid and solid is 90, the Cd' s leaching ratio exceed the percent of 70. At the time pH is about 7, the leaching concentrations of heavy metals are the lowest. When the grain size is the bigger or little, the leaching concentrations of heavy metals are lower, however when the grain size is 250-900 microm, the concentrations are higher. After fly ash melt in the high temperature, the lixiviate toxicity of heavy metals greatly reduce, which explains that the effect of melting on heavy metals' stabilization is very good.
Alkaline leaching of coal by the mechanochemical treatment  [PDF]
Balá? Peter,Turèániová ?udmila
Acta Montanistica Slovaca , 1998,
Abstract: The possibility of application of a new process GACL (Grinding and Aqueous Caustic Leaching) for the reduction of mineral components in the brown coal Nováky was tested. The simultaneous grinding and chemical leaching enable us to extract 41 % total sulphur, 95 % arsenic and to reduce the ash content to 43 %. The process proceeds at the atmospheric pressure, temperature 90oC and in diluted NaOH solutions (5 %).
Research of metallurgical wastes as pigments
Feèko Peter,Farka?ová Adriana,Rojík Petr,èablík Vladimír
Acta Montanistica Slovaca , 2002,
Abstract: The goal of the work was verification of utilization of metallurgical wastes-sludge from Nova Hu , a.s. Ostrava, T inecké elezárny, a.s. T inec and Vítkovice, a.s. as a pigments. Here as samples originated as waste materials during iron production there was assumption of their utilization as ferric pigments. However neither by application of bacterial leaching or calcination, quality of these materials corresponding to their utilization as ferric pigments was, not obtained. When succeeded produce material with fine red colour, thus leach of given treated waste was unsatisfactory.
Leaching of lead from zinc leach residue in acidic calcium chloride aqueous solution  [PDF]
Le Wang,Wen-ning Mu,Hong-tao Shen,Shao-ming Liu,Yu-chun Zhai
- , 2015, DOI: https://doi.org/10.1007/s12613-015-1094-y
Abstract: A process with potentially reduced environmental impacts and occupational hazards of lead-bearing zinc plant residue was studied to achieve a higher recovery of lead via a cost-effective and environmentally friendly process. This paper describes an optimization study on the leaching of lead from zinc leach residue using acidic calcium chloride aqueous solution. Six main process conditions, i.e., the solution pH value, stirring rate, concentration of CaCl2 aqueous solution, liquid-to-solid (L/S) ratio, leaching temperature, and leaching time, were investigated. The microstructure and components of the residue and tailing were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). On the basis of experimental results, the optimum reaction conditions were determined to be a solution pH value of 1, a stirring rate of 500 r·min?1, a CaCl2 aqueous solution concentration of 400 g·L?1, a liquid-to-solid mass ratio of 7:1, a leaching temperature of 80°C, and a leaching time of 45 min. The leaching rate of lead under these conditions reached 93.79%, with an iron dissolution rate of 19.28%. Silica did not take part in the chemical reaction during the leaching process and was accumulated in the residue.
Alkaline leaching of mechanically activated berthierite and boulangerite
Marcela Achimovi?ová,Peter Balá?
Acta Montanistica Slovaca , 2006,
Abstract: In this study, changes in the surface area, morphology and the leachability of antimony from mechanically activated berthierite FeSb2S4, boulangerite - Pb5Sb4S11 by a high-energy planetary mill were investigated. It appears, that an extraction of antimony from these complex sulphosalts in the alkaline solution of sodium sulphide is positively affected by the mechanical activation. An influence of milling on the mineral particle size and shape was studied by scanning electron microscopy. The temperature dependencies of alkaline leaching of berthierite were investigated in the interval of 323-363 K. The resulting experimental activation energies EA were 0.11 kJ.mol-1 and 6.78 kJ.mol-1 for mechanically activated berthierite. The values EA are characteristic for a process controlled by diffusion as the rate controlling step of leaching reaction.
Desulphurization Characteristic of Industry Alkaline Wastes during Coal Combustion  [PDF]
Bin Zheng, Chunmei Lu
Journal of Electromagnetic Analysis and Applications (JEMAA) , 2009, DOI: 10.4236/jemaa.2009.11007
Abstract: The desulphurization characteristics of four sorts of industry alkaline wastes and one sort of limestone were studied by means of flue gas analyzer and the high temperature tube reactor. Pore structure and desulphurization product char-acteristic were investigated respectively by mercury porosimeter and XRD diffraction technology. The reasons why wastes and limestone hold the different desulphurization capability were deeply discussed. The result shows that white clay and carbide slag could capture the release of sulfur at 800-1100℃. Salt slurry and red mud could capture the re-lease of sulfur at first stage at 800-900℃. But when the experimental temperature rises to 1000℃, the sulfur capture abilities of them depress. Pore structures of waste are higher than that of limestone. This makes the sulfation reaction goes further. To sum up, wastes have better sulfur capture ability.
Hydrolysis of tanned leather wastes under alkaline, acidic and oxidative conditions
Boti? Tatjana,Ili?kovi? Nade?da
Hemijska Industrija , 2006, DOI: 10.2298/hemind0602023b
Abstract: Different wastes in large quantities are the outcome or the by-product of processes in the tanning industry. The largest part of solid wastes is collagen based and obtained in the reprocessing steps of tanned and non-tanned products. The quality collagen substance obtained from wastes of the leather industry used as a supporting material in many reprocessing industries. Hydrolysis is the basic step of collagen processing, namely the shortening of its polypeptide chain. The main goal of this investigation was to examine the influence of the following parameters on the extent of collagen hydrolysis: type and quantity of reagent used for hydrolysis temperature of hydrolysis, pH, duration of hydrolysis as well as the dimensions of the "shavings" samples. The change of molar mass during hydrolysis was monitored by UV-spectroscopy. Special attention was paid to the dechroming process of the collagen hydrolysate.
Zinc recovery from iron and steel making wastes by conventional and microwave assisted leaching
Ján Vere?,?tefan Jakabsky,Michal Lovás
Acta Montanistica Slovaca , 2011,
Abstract: Significant quantities of sludge and dust are generated as a waste material or byproduct every day from iron and steel industries.Nowadays The occurrence and recovery of metallurgical wastes from steelmaking and iron making processes is a great problem, mainlydue to the big amount and environmental pollution of these wastes by heavy metals. The future technology of fine-grain metallurgicalwastes treatment is mainly the thing of ecological and financial limits. This work explains the removal of zinc from blast furnace sludgeby hydrometallurgical process. The aim of this work was to carry out a chemical, physical, structural, and morphologicalcharacterization of these waste materials and subsequently to find out the best suitable method for the hydrometallurgical treatment.The experimental work includes full plant experiments. Extraction conditions such as the effect of microwave power, leaching agent,acid concentration, S/L ratio and extraction time on the zinc removal efficiency were evaluated. The main goal is to set the bestconditions to transfer zinc into the solution while the iron should to remain in the solid phase.
Deselenization and detellurization of precious-metal ore concentrates by swelling oxidizing roasting and successive alkaline leaching  [PDF]
Fu-yuan Zhang,Ya-jie Zheng,Guo-min Peng
- , 2017, DOI: https://doi.org/10.1007/s12613-017-1389-2
Abstract: A new technique of swelling oxidizing roasting and alkaline leaching was proposed for deselenization and detellurization of precious-metal ore concentrates. Alkali-metal and alkaline-earth-metal chlorides and carbonates were preliminarily selected as swelling agents. The roasting removal rate and alkaline leaching rate of selenium and tellurium were investigated, and NaCl was selected as an appropriate swelling agent. Furthermore, the effects of various factors on the selenium gasification rate and leaching rate of selenium and tellurium were investigated. The results show that the selenium gasification rate reaches 88.41% after swelling oxidizing roasting for 2 h at 510°C using an NaCl dosage coefficient of 100 and a sulfuric acid dosage coefficient of 1.3; the amorphous elemental tellurium is completely transformed into TiO2. The roasted product is subjected to alkaline leaching using a 100 g/L NaOH solution, which results in a selenium leaching rate of 10.51%, a total selenium removal rate of 98.92%, and a tellurium leaching rate of 97.64%. In the alkaline leaching residue, the contents of selenium, tellurium, gold, platinum, and palladium are 0.7825%, 5.492%, 8.333%, 0.2587%, and 1.113%, respectively; the precious metals are enriched approximately sixfold.
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