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By Jun Li, Lingling Zhang, Daqiang Cang, Guizhou Zhao

Pilot trial of direct modification of molten blast furnace slag and production of high acidity coefficient slag wool fibers were investigated nearby a blast furnace. Molten blast furnace slag discharged from blast furnace and then directly flow into specialized modification furnace and quartz was simultaneously added into the molten slag as modification agent. The modified molten slag was electric heated to 1500–1550 °C and then the melt was produced into slag wool fibers through high-speed centrifugation method. Melt with acidity coefficient of 1.2, 1.4, 1.6 and 1.8 were investigated and fibers with corresponding acidity coefficient were produced. Slag wool fibers with shot content of 5.5, 5.8, 6.2, 6.8% and average diameter of 4.5, 4.9, 5.6, 6.4 lm for four samples were successfully produced, respectively. Total energy consumption and production costs decreased by 50–70% compared to traditional cupola furnace method. This method provides an energy-saving and emission-reduction technology for the direct utilization of molten blast furnace slag.

Mar 1, 2018

A strategy is presented for a relatively. "low-tech" means for decontamination of streams . containing .low concentrations of toxic metals. Metal ion solutions were . circulate through fluidized beds of activated carbon which support bio-films ?of bacteria .that naturally excrete exopolysaccharides. The attached 'biomass is shown to significantly enhance nickel, cadmium and silver extraction from dilute solutions (5- l00mg/l). By heat treating (at 300º C) the metal/biomass/carbon particles, bio-sorbed silver was subsequently fixed to the carbon surface. This approach to metal decontamination may therefore also provide a route for dispersing and fixing catalytic metal particles over an activated carbon surface.

Jan 1, 1991

By W. G. Davenport

Chapter 11 determined the combinations of industrial oxygen, oil and blast preheat that will steadily produce 65% Cu matte from pure chalcopyrite concentrate. It showed that the . combinations are described by a flat plane. It also showed that the minimum energy requirement for making 65% Cu matte occurs with maximum oxygen enrichment, zero oil and zero blast preheat. This chapter examines the, effect of matte grade on industrial oxygen, oil and preheat requirements.

Jan 1, 2001

By E. Fockedey

he destruction of free cyanide on a Co3O4 doped carbon felt was studied. The experiments were done with an eiectrochemical filter press cell on dilute alkaline solutions containing 250 mg/l NaCN. No chloride ions were added to the solutions. The cobalt oxide protects the felt against corrosion and has a catalytic effect on the degradation of the cyanide. This kind of electrode allows working with current density as high as 1200 Aim without any visible degradation of the felt. The most interesting results were obtained with a current density of 400 Aim' at which the cyanide concentration can be lowered to 5 mg/l with a current efficiency of more than 70 % and a specific energy consumption of about 10 kWh/ kg CN.

Jan 1, 1998

By Monica C. Pinto, Gustavo H. Nalon, José C. L. Ribeiro, Rita de C. S. S. Alvarenga, Leonardo G. Pedroti, Lucas A. F. Fioresi

This study aims to evaluate the influence of mortar’s mechanical properties on the behavior of clay masonry. Experimental studies were performed using prisms of clay blocks under axial compression. The clay units were produced with a clay from Tres Rios, Rio de Janeiro, Brazil and had compressive strength of 4.9 MPa. Two mortar compositions were used, which had compressive strength of 94.7 and 50.4% of the clay blocks’ net area compressive strength. It was noticed a slight increase on the prism’s compressive strength with the increase of the mortars’ compressive strength and stiffness. Prisms made with flexible mortars had a ductile failure and collapsed under lower compressive stresses, while prisms made with stiff mortars resisted higher compressive stresses, but had a brittle failure ,crushing the blocks. A very strong mortar is not recommended. Using more flexibl mortars does not compromise the strength and stiffness of the masonry and prevents an excessively brittle failure of the structure.

Mar 1, 2017

By Alan Branham

The Mike deposit is a large, low grade, oxide, gold-copper system found at the intersection of two major faults that bound the Carlin Window, Eureka County, Nevada. Disseminated gold occurs within metamorphosed and hydrothermally altered silty limestone (Silurian-Devonian Roberts Mountains Formation), beneath 182 m (600 feet) of barren Tertiary sediments and tuffs. A supergene copper oxide blanket occurs beneath and locally overlaps the lower portion of the gold zone. Decalcification argillization, silicification, and brecciation are superimposed on earlier calcsilicate hornfels and marbles. Altered dikes and sills intrude the gold zone and are locally auriferous.

Jan 1, 1995

By Zhigang Zak Fang, Michael L. Free, Jaehun Cho, Syamantak Roy, Amarchand Sathyapalan

Leaching characteristics of impurity removal from the Upgraded Titania Slag (UGS) using hydrochloric and boric acids has been investigated. Specifically, this study has focused on removal of iron oxides from the UGS that has been reduced by hydrogen gas and magnesium at 750oC for 5 hours. Reduced UGS is mainly composed of titanium hydride and impurities like iron oxides, silicon oxide, aluminum oxide, and magnesium oxide. The concentration of hydrochloric and boric acids and the leaching temperature have been chosen as the prime variables to identify the optimum conditions and leaching characteristics for removal of iron oxides. It was observed that under the constraint that 1 wt % of titanium hydride loss is the maximum amount tolerable, 0.1M HCl with 1M boric acid and 90oC are the most effective parameters for iron removal from the reduced UGS. Also, the overall rate of reaction seems to follow interfacial reaction controlled kinetics. The calculated activation energy of the reaction is 73.90kJ/mol.

Jan 1, 2016

By Wang Chen

COREX process is briefly introduced. A static model combining a set of mass and heat balance equations has been developed. Taking the specified inputs from the graphical user interfaces, the model is capable of calculating the consumption of raw materials and fluxes, the volume and composition of the slag and the volume and composition of the generator gas. The model enables the examination of the changes of materials and energy flows induced by the variations of operational parameters and raw materials chemical analysis. The model allows a detailed process analysis and adjustment of the plant operation and can thus be used to improve plant operation.

Jan 1, 2008

By Wei Lv, Xuewei Lv, Senwei Xuan, Chenguang Bai, Kai Tang

The contact angle between six iron ores and water were determined by the capillary pressure method with cyclohexane as the perfect wetting liquid. The factors influencing the contact angle were discussed, and a relationship between the content of oxy–hydroxides and the contact angle of iron ores was obtained. The results show that the ore F has the lowest contact angle but the ore D get the biggest, which are 32.09° and 78.16°, respectively. The volume fraction of oxy–hydroxides is linearly dependent on the contact angle. The contact angle decreased with increasing the volume fraction of Fe2O3*H2O.

Mar 1, 2017

By Lei Zhang, Shining Chen, Lina Wang, Pu Liu, Benquan Fu, Jiannyang Hwang

A PFS(polymeric ferric sulfate) coagulation-photocatalytic oxidation technology was used for advanced treatment of coking wastewater from secondary biological treatment. Effects of some key factors on TOC removal rate were investigated, and the results were compared with those of the common photocatalytic oxidation technology under the operating parameters of the photocatalytic oxidation defined. Single factor experimental results showed that TOC removal rate could reach 81%, when optimal operating conditions were as follows: TiO2 loading: 4.0g/L, irradiation time: 4h, initial pH is 5.1and PFS dosage:700mg/L. PFS coagulation and photocatalytic oxidation have synergistic effect, which is meaningful for highly efficient treatment of coking wastewater

Jan 1, 2015

By Yongqi Sun, Zuotai Zhang

Our study investigated the influence of P2O5 and B2O3 on the viscosity and crystallization behavior of Ti-bearing blast furnace (Ti-BF) slags for the purpose of Ti extraction. The investigation of the crystallization behaviors were carried out using a single hot thermocouple technique (SHTT) and the viscosity was obtained by rotating cylinder method. For the viscosity, the results showed that P2O5 substantially increased the slag viscosity. P2O5 is a network-forming oxide, which increased the degree of polymerization of slags and accordingly increased the slag viscosity. However, both of slag viscosity and apparent activation energy for viscous flow remarkably decreased with B2O3 addition. As a typical network forming oxide, B2O3 was introduced into the network and existed dominantly as 2-D structure, BO3 triangular, which caused a simpler structure and a decreasing slag viscosity. As for the crystallization behaviors of Ti-BF slags, both P2O5 and B2O3 enhanced the crystallization trend of rod-shape rutile and suppressed the crystallization trend of dendrite CaTiO3. Therefore the added P2O5 and B2O3 caused the primary phase change from CaTiO3 to rutile. Additionally, it was found that the rod-shape rutile showed a 1-D growth, whereas the dendrite CaTiO3 showed a 3-D growth style.

Jan 1, 2015

By Zemin Ma

A novel chromate [Cr(VI)] reducing bacterium was isolated from chromite ore processing residue disposal site of China and identified as a Leucobacter sp. by 16S rRNA gene sequence homology. The minimum inhibitory concentration of strain CRB1 was 820 mg l-1 of Cr(VI). The reduction of Cr(VI) occurred only under aerobic conditions. With an initial concentration of 2.5×108 cells ml-1, 1800 mg l-1 of Cr(VI) was reduced entirely within 38 h under the optimum conditions, at 30 °C and pH 9.0. Increasing Cr(VI) concentrations prolonged reduction process and higher cell densities meant quicker reduction. A blue precipitate was produced during chromate reduction of strain CRB1, which was binding to the surface of bacterial cells and determined as trivalent chromium with electron paramagnetic resonance (EPR) spectrometry. The conspicuous chromate reduction ability of Leucobacter sp. CRB1 suggested a potential for bioremediation of Cr(VI) containing wastes.

Jan 1, 2008

By lndu S. Das

An analytical simulation of the material characteristics of Inconel 718 is developed and bounds for mechanical and microstructural stability are obtained for isothermal and temperature-dependent cases. Experimental flow stress data using hot compression tests are reported for a wide range of temperature and strain at various strain rates. A parametric study of strain rate sensitivity, dissipation and entropy are presented. A complete set of processing maps delineating the stable and unstable regions are developed to help define the most efficient means of manufacturing an Inconel product.

Jan 1, 1992

By Brajendra Mishra, Mark L. Strauss, Gerard P. Martins

Europium is a critical material required for LED, florescent lamp, cell phone screen, and flat panel display production. This process recycling europium from waste lamp phosphors is an innovative method to supply europium. The selective reduction and precipitation method using sulfate precipitation is investigated to recover high-purity europium from yttrium-europium mixed solutions.

Mar 1, 2017

By C. A. Natalie

Prediction of average residence times for different particle size intervals during sulfide roasting was investigated. Calculations were done to predict average residence times using a model which employs empirical correlations for elutriation constants. Experimental average residence times were determined using a continuous., six inch diameter,. fluid bed roaster and compared with calculated residence time values. Comparison of calculated and experimental data showed that geometry effects may have .been significant when attempting to apply elutriation data to this roaster.

Jan 1, 1985

By Jiangtao Li, Zhongwei Zhao, Xingyu Chen, Xuheng Liu

The method of ultrasonic-assisted leaching was used to extract vanadium from the stone coal, with alkali as leaching reagent. The effects of ultrasonic power, concentration of alkali, reaction temperature, liquid-solid ratio and reaction time were investigated, respectively. The optimal ultrasonic leaching condition for vanadium extraction is as follows: ultrasonic power 230W, concentration of alkali 5%, liquid-solid ratio 3:1, reaction temperature 90℃ and reaction time 1h. The leaching rate of vanadium reaches 76.4% under the optimal condition, which is 12.2% higher than that of non-ultrasonic leaching. The reason on enhancing the leaching rate of vanadium by ultrasonic leaching was discussed. It is indicated that the ultrasonic cavitation can increase the surface area of mineral, which is beneficial to facilitate the reaction rate. Keywords: stone coal; vanadium; alkaline leaching; ultrasonic

Jan 1, 2014

By Uday Pal, Shizhao Su, Thomas Villalon

Compared with the current Hall–Héroult process for smelting aluminum, the Solid Oxide Membrane (SOM)-Based electrolysis process brings various advantages such as simplified design, lower cost, lower energy use, and many other environmental bene fits. However, the state-of-the-art SOM electrolysis process is limited by the solid oxide membrane’s stability and its compatibility with the molten salt and the electrode materials. This work will identify cost-effective molten salt compositions and membrane materials/architecture along with electrodes and current collectors that are all chemically compatible and provide optimum electrochemical properties for efficient aluminum oxide electrolysis.

Mar 1, 2017

By He De-wen

Based on the principle of life cycle assessment (LCA), municipal solid waste management (MSWM) was analyzed by life cycle inventory method. According to the system expansion and substitution method, the content and frame of life cycle analysis is summarized and applied to municipal solid waste. On the basic of feasibility research of life cycle analysis on MSWM, the paper put forwards complete and concrete ?three changes? measures under life cycle analysis on MSWM. Some aims of MSWM can be achieved under above conditions of LCA on MSWM: to improve the current system efficiency of MSWM; to enhance the serve quality of MSWM, to increase recycle garbage from MSW; to reduce waste amount and reach minimization and innocuity aim of MSWM; to help the departments of MSWM to get over all difficulties to realize their ideal goals.

Jan 1, 2009

By Chr. Kersch

This project further develops supercritlcal fluid extraction as an industrial soil remediation process. Heavy metals are removed from sand using CO2, The effect of the type of complexing ligands, pressure and water content on the extraction efficiency is investigated.

Jan 1, 1999

By W. Hoffelner

Plasma technology has become increasingly important for the treatment of several types of waste (toxic, nuclear, metal-bearing scrap). Plasma furnaces combine the advantages of a closed hearth process with a very versatile (several plasma gases can be employed) and effective heat source. It can be successfully used for recovery of metals with subsequent purification and/or vitrification of residuals from drosses or filter dusts.

Jan 1, 1994