Studija uklanjanja srebra iz otpadaka nakita flotacijskim procesom

This article is a discussion on the proposed solution of using the flotation process to separate metals from non-metallic components present in the scrap generated while jewellery goods are being ground. For the sake of the studies analyzed, a dedicated laboratory station was established.Članak je rasprava na predloženu soluciju rabljenja flotacijskog procesa za izdvajanje metala iz nemetalnih komponenti nazočnih u otpadu koji nastaju pri izradi nakita. Glede analiza studije utemeljena je odgovarajuća laboratorijska stanica

Vacuum refinning cooper blister to remove antimony

A research on kinetics of antimony evaporation from molten copper blister was made in a vacuum induction melting (VIM) furnace at temperatures of 1 473 and 1 523 K, and operating pressures of 8 - 133 Pa. The evaporation rate of Sb was found to be first order with respect to your content in the melt. The overall mass transfer coefficient of antimony evaporation from cooper blister are from 1,82×10-5 ms-1 to 3,43×10-5 ms-1 at 1 473 K (8 Pa) - 1 523 K (133 Pa)

Research on the reduction of cooper slag using an alternative coal range

Blister copper smelting in a flash furnace results in the generation of slag with a Cu content greater than 15 percent. In the process of reduction in an electric furnace, coke or coke breeze is used as a carbon-bearing material. The presented work shows the results of studies on the reduction of the slag with a carbon flotoconcentrate as a substitute for coke breeze. The microstructure, chemical composition and phase composition of slag samples were analyzed. Based on the results of chemical composition of the Cu-Pb-Fe alloy and the post-reduction slag, it was shown that carbon flotoconcentrate might be considered as an alternative for currently used reducers

Behaviour of iron during reduction of slag obtained from copper flash smelting

In a technological process of copper production in the flash smelting furnace, slags with high metal contents, such as copper, lead and iron, are generated. These slags differ in their chemical compositions from slags obtained in processes of copper concentrate flash smelting or bath smelting. With the technology used at KGHM, the slag discussed in the article is processed during smelting reduction that is carried out in the electric furnace. As a result, a Cu-Pb-Fe alloy is obtained and subjected to the converting process along with waste slag which contains ca. 0,5 % mass Cu. The article presents an analysis of results of the research on behaviour of iron in the course of slag reduction where diverse fine-grained carbon-bearing materials function as reducers

The obtained of concentrates containing precious metals for pyrometallurgical processing

In the presented study the flotation process has been proposed as a method of enrichment of silver-bearing jewellery waste. This method, traditionally used for the enrichment of non-ferrous metal ores, is based on differences in wettability between individual minerals. Flotation concentrate, enriched with Ag, was subjected to further processing by the pyrometallurgical method in order to produce silver from these wastes

Application of waste anthracite dust in the process of copper matte smelting

This study presents the results of research on the process of smelting of copper matte with the use of anthracite waste dust as fuel. A method of introducing this carbon-bearing waste into the technological process carried out in a shaft furnace in the form of an additive to briquettes with copper concentrate was developed. These briquettes were tested for the required strength properties

Recovery of precious metals from waste materials by the method of flotation process

The article presents the investigation results upon recovery of precious metals from electronics waste and used ceramic catalytic converters. Various frothing agents which generate stable and abundant foam as well as collectors and pH regulators have been used in the investigations. The tests were conducted with the use of laboratory flotation device

Interplay between magnetic properties and Fermi surface nesting in iron pnictides

The wave-vector q and doping (x,y) dependences of the magnetic energy, iron moment, and effective exchange interactions in LaFeAsO{1-x}F{x} and Ba{1-2y}K{2y}Fe2As2 are studied by self-consistent LSDA calculations for co-planar spin spirals. For the undoped compounds (x=0, y=0), the minimum of the calculated total energy, E(q), is for q corresponding to stripe antiferromagnetic order. Already at low levels of electron doping (x), this minimum becomes flat in LaFeAsO{1-x}F{x} and for x>=5, it shifts to an incommensurate q. In Ba{1-2y}K{2y}Fe2As2, stripe order remains stable for hole doping up to y=0.3. These results are explained in terms of the band structure. The magnetic interactions cannot be accurately described by a simple classical Heisenberg model and the effective exchange interactions fitted to E(q) depend strongly on doping. The doping dependence of the E(q) curves is compared with that of the noninteracting magnetic susceptibility for which similar trends are found.Comment: 17 pages, 5 figure

Effects of a bath composition on aluminium loss during Ti-Al alloy smelting in a vacuum induction furnace

In the paper, results of a kinetic analysis of aluminium evaporation from binary Ti-Al alloys during their smelting in a vacuum induction furnace are presented

Electron-phonon renormalization of the absorption edge of the cuprous halides

Compared to most tetrahedral semiconductors, the temperature dependence of the absorption edges of the cuprous halides (CuCl, CuBr, CuI) is very small. CuCl and CuBr show a small increase of the gap $E_0$ with increasing temperature, with a change in the slope of $E_0$ vs. $T$ at around 150 K: above this temperature, the variation of $E_0$ with $T$ becomes even smaller. This unusual behavior has been clarified for CuCl by measurements of the low temperature gap vs. the isotopic masses of both constituents, yielding an anomalous negative shift with increasing copper mass. Here we report the isotope effects of Cu and Br on the gap of CuBr, and that of Cu on the gap of CuI. The measured isotope effects allow us to understand the corresponding temperature dependences, which we also report, to our knowledge for the first time, in the case of CuI. These results enable us to develop a more quantitative understanding of the phenomena mentioned for the three halides, and to interpret other anomalies reported for the temperature dependence of the absorption gap in copper and silver chalcogenides; similarities to the behavior observed for the copper chalcopyrites are also pointed out.Comment: 14 pages, 5 figures, submitted to Phys. Rev.