Single Cr (VI) reduction and coupled reduction/stabilization (R/S) processes were evaluated at pilot scale to determine their effectiveness to treat chromite …

Semantic Scholar extracted view of "A New Method (Ball Milling and Sodium Sulfide) for Mechanochemical Treatment of Soda Ash Chromite Ore Processing Residue." by Yan Sun et al.

Other more reactive metals can be used to reduce the ore. Titanium is produced by reducing titanium (IV) chloride using a more reactive metal such as sodium or magnesium. As you will see if you read the page about titanium extraction, this is the only way of producing high purity metal.

Pilot scale treatment of chromite ore processing residue using sodium sulfide in single reduction and coupled reduction/stabilization processes

Bentonite clay production process features ore mining, sodium activation (if required), drying, milling, classifying, pelleting, etc. Grinding and drying are key steps.

Single Cr (VI) reduction and coupled reduction/stabilization (R/S) processes were evaluated at pilot scale to determine their effectiveness to treat chromite ore processing residue (COPR). Sodium sulfide was used as the reducing agent and cement, gypsum and lime were tested as the stabilizing agents.

We investigated a method for delivering ferrous iron into the subsurface to enhance chemical reduction of Cr (VI) in chromite ore processing solid waste …

In the context of its processing, gold deposits are typically classified, for the purposes of simplification, as: 1) free milling, and 2) refractory ores (including complex and carbonaceous). Based on their mineralogical characteristics and their mineral processing techniques required to liberate them, however, gold ores can be classified further.

cyanide process, method of extracting silver and gold from their ores by dissolving them in a dilute solution of sodium cyanide or potassium cyanide. The process was invented in 1887 by the Scottish chemists John S. MacArthur, Robert W. Forrest, and William Forrest. The method includes three steps: contacting the finely ground ore with the ...

Sodium chromate is produced via the soda-ash roasting of chromite ore with sodium carbonate. After the reaction, nearly 15 pct of the chromium oxide remains unreacted and ends up in the waste stream, for landfills. In recent years, the concern over environmental pollution from hexavalent chromium (Cr6+) from the waste residue has become a major …

Effective Cr (VI) reduction and immobilization in chromite ore processing residue (COPR) contaminated soils by ferrous sulfate and digestate: A comparative investigation with typical reducing agents

The global decrease in ore mineral grades and increase in ore mineralogical complexity has triggered the modern mining industry and research communities to search for efficient methods of processing ores which were initially considered uneconomic [ 1, 2 ]. Gold-bearing copper minerals are common occurrences in many gold deposits and are …

Remediation of hexavalent chromium contamination in chromite ore processing residue by sodium dithionite and sodium phosphate addition and its mechanism.

In this process, molten sodium chloride (common salt) is electrolyzed using a graphite anode and a ring-shaped iron cathode. The two electrodes are separated by a wire gauge partition to avoid the mixing of sodium and chlorine so formed.

In the intricate and technologically advanced realm of mineral processing, the quest for efficiency and sustainability remains paramount. The mining industry,

We investigated a method for delivering ferrous iron into the subsurface to enhance chemical reduction of Cr(VI) in chromite ore processing solid waste (COPSW) derived from the production of ferrochrome alloy. The COPSW is characterized by high pH (8.5−11.5) and high Cr(VI) concentrations in the solid phase (up to 550 mg kg-1) and …

Hexavalent chromium in soda ash Chromite Ore Processing Residue (COPR) is harmful to the environment, it is imperative to develop a low cost, efficient, and effective treatment.

1. Introduction. The soda ash roasting process produces Chromite Ore Processing Residue (COPR) containing 1130–8500 mg/kg carcinogenic hexavalent chromium (Cr (VI)) due to the industrial incomplete leaching ( Du and Chrysochoou, …

The method utilizes ferrous sulfate (FeSO4) in combination with sodium dithionite (Na2S2O4) to inhibit premature precipitation of Fe in the subsurface. We conducted both laboratory and field tests to evaluate the performance of FeSO4/Na2S2O4 solutions in treating the chromite ore processing waste and associated impacted …

Hexavalent chromium in soda ash Chromite Ore Processing Residue (COPR) is harmful to the environment, it is imperative to develop a low cost, efficient, and effective treatment. Herein, a new method (ball milling + sodium sulfide) was developed for mechanochemical treatment of water-leached COPR (W-COPR, about 900 mg/kg non …

However, the coke breeze consumption and the proportion of ore-dust mix vary among the three types of sintering processes. This study provides an illustrative …

Its actual dispersive effect on kaolinite under iron-ore flotation conditions has received very limited attention, however. The presence of hydrolyzable metal cations in process water further complicates sodium silicate—kaolinite interactions.

Most of the gold extraction from ore is accomplished by the implementation of an alkaline cyanide leaching process. The chemical recovery of gold can be defined by two different operations: the …

Remediation of hexavalent chromium contamination in chromite ore processing residue by sodium dithionite and sodium phosphate addition and its mechanism

Considering these uses, the oxidizing roasting process of an indigenous chromite ore to prepare industrial sodium chromate was investigated in this study. The effects of sodium carbonate to chromite mole ratio, reaction temperature, contact time and its thermodynamics-cum-kinetics behaviour were also discussed.

For the mechanism of sodium sulphate, Na + is able to liberate the hosted nickel and iron within lizardite, while SO 42– is the sulphur source for the formation of Fe–FeS eutectic compound which can decrease the characteristic fusion temperatures to promote the growth of ferronickel grains.

The studies were based on controlled pH, which eliminated the dispersive effect of sodium silicate induced by increasingpulp pH, in order to simulate the conditions of iron-ore processing.

In the traditional production process of Cr 2 O 3, these chromium salts are first produced through high–temperature oxidation roasting of chromite ore and sodium carbonate (Na 2 CO 3 ), followed by leaching, multistage acidification, and crystallization by evaporation ( Dhal et al., 2013 ).

Getting useful crafting materials out of the world-generated Ore Blocks in GregTech 6 has become less forumlaic than it was in GregTech 5, but more optional side paths have been added. This document details how processing chains evolve from the manual 'forge age' through to 'electrical age', and finally contains a reference listing of byproducts by ore …

The technological feature of ore processing is an important research content in the early stage of ore technical-economic evaluation, industrial index formulation, and …