microwave heating of refractory minerals

Sep 12, 2003· Vast amounts of energy are used in crushing and grinding of minerals in mineral processing operations. Heating with microwaves prior to grinding provides a method that could potentially significantly lower energy consumption. The technology is described herein.

Bradhurst and Worner, 1990 discuss applications of microwave heating in mineral processing and pyromet-allurgy, including drying of coal, gold extraction and ore reduction (see also Standish and Huang, 1991 and Standish and Worner, 1991). Haque, 1987 has discussed microwave pre-treatment of refractory gold ores.

wave heating In minerals processing Early research into microwave heating of minerals involved establishing heating rates.5,6 The observation that many miner­ als coupled well with microwaves while gangue materials did not, suggesthat one of the benefits of microwave heating in mineral processing is selective heating of valuable mineral phases.

period of several years is the use of microwave heating technologies to improve the efficiency of various mineral processing unit operations including: leaching, refractory gold ore treatment ...

Jul 18, 2013· One such area which has shown particular promise over a period of several years is the use of microwave heating technologies to improve the efficiency of various mineral processing unit operations including: leaching, refractory gold ore treatment, grindability and liberation and coal grinding.

Jan 01, 2010· Therefore, this study investigated the removal of sulfur and arsenic from a refractory flotation gold concentrate by microwave heating. 2. Experimental 2.1. Ore sample. The main minerals in the refractory gold concentrate were arsenopyrite, pyrite, pyrrhotite and quartz.

The main idea of microwave/infra-red (MW/IR) ore sorting is to use MW heating to selectively heat ore particles and separate particles based on their temperatures. This is based on the assumption that during the MW exposure some metal rich minerals tend to heat more than other minerals.

Microwave heating differs from conventional heating due to the fact that the microwave heating occurs via direct microwave material interaction, while the conventional heating requires the heat to be transferred from the external heat sources [].As in situ heat generation alleviates the heat transfer limitations of the conventional ovens, materials can be processed at a faster rate via the use ...

Naturally occurring minerals and reagent-grade compounds were tested to determine their receptivity to microwave heating. The maximum temperature achieved for the samples and the time required to reach temperature are reported. A description of the microwave oven and a thermocouple technique that accurately measures and continuously records the temperature of samples during irradiation are ...

Jun 01, 2020· Microwave heating and roasting tests were performed in a Kenwood Microwave operating at 800 W and 2.45 GHz. This single incident power was used in all the tests. The microwave heating response of the concentrate was determined by heating samples with masses between 10 and 60 g in crucibles made from quartz tubing.

Dec 10, 2011· The information compiled in this chapter demonstrates that microwave energy has the potential for application in mineral treatment and metal recovery processes such as heating, drying, grinding, leaching, roasting, smelting, carbothermic reduction of oxide minerals, pretreatment of refractory gold concentrate or ore, spent carbon regeneration ...

Microwave-assisted digestion (MAD) of mineral samples has been developed to a usable technique over the past ten years or so. Modern laboratory microwave digestors are essentially the same as kitchen microwave ovens, albeit with chemically resistant surfaces, very advanced microprocessor controlled power output and a range of safety features.

After roasting, microwave heating or alkaline pressure oxidation, the gold cyanidation ratio reached 82.37%, 81.26% and 71.09% respectively. Roasting was an effective, reliable and mature technique to oxidize sulfide minerals and carbonaceous matters.

Microwave pretreatment of a double refractory gold ore - ScienceDirect. Double refractory gold ores, such as Barrick's Goldstrike ore, contain both pyrite and carbonaceous matter and the latter results in the loss of gold from solution during cyanide leaching.

The Use Of Microwave In Refractory Ore Benification. microwave assisted refractory gold processingGold Ore microwave heating of refractory minerals Get Price iron beneficiation in refractory bricks A layered refractory lining for a furnace for use in a titanium ore beneficiation process wherein a titanium oxide-rich Iron Ore Gold Benification ...

Microwave heating has also been applied by Choi et al. [17] to perform pre-treatment, ... important for the recovery of precious metals from complex or refractory minerals. To increase the

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Sep 01, 2007· With regards to the application of microwaves to refractory gold ores, Haque, 1987a, Haque, 1987b has studied the microwave pretreatment of refractory sulphidic ores and achieved gold extractions of over 98%. However, there is no information published on the microwave processing of the double refractory gold ores.

It uses mineral absorption properties to heat minerals. In this way, gold, arsenic and sulfur can be separated from ores. The technical advantages of microwave roasting are selectively heating materials, fast heating rate and high heating efficiency. Microwave heating has the effect of reducing the temperature of chemical reaction.

electromagnetic-heating-stress-damage process. Microwave heating is simulated at sample-scale and the result-ing stress-damage response is examined at micro-scale where minerals with contrasting thermo-mechanical characteristics are stacked as lamellae, instead of nested internally as in previous representations. A three-

The microwave-assisted reduction behaviours of two low-grade iron ores having a similar Fe content of 49wt% but distinctly different mineralogical and liberation characteristics were studied. Their performances in terms of the iron grade and recovery as obtained from statistically designed microwave (MW) roasting followed by low-intensity magnetic separation (LIMS) experiments were compared.

2.1. Minerals in microwave field Conventional heat treatment of minerals is a process with high-energy consumption and it is not economical. Hence, researchers, searched for processes that are more effective. It is reported in a review paper by Xia and Pickles, 199716, that the earliest work on the microwaving of minerals began with a study of ...

Jun 17, 2016· Microwave energy can be used to create high temperatures (> 1700° C for alumina) in refractory materials. Energy conversion takes place with a very good efficiency (90% in the conversion process of microwaves to thermal energy) if an appropriate applicator is utilized.

The effect of power level on the microwave heating characteristics of a variety of reagent-grade chemicals and minerals has been determined in a Bureau of Mines study. Heating rates of the powdered samples are presented for incident power ranging from 500 to 2,000 W at 2.45 GHz.

Effect of microwave heating on the temperature of various minerals (500 W, 2450 MHz, 4min radiation) Microwave Heating Applications in Mineral Processing 85

The microwave pretreatment of a typically refractory flotation gold concentrate was investigated. The results demonstrated that a maximum gold recovery of 97% was achieved, and that gold recoveries of the refractory gold concentrate quickly increased to the maximum with microwave heating time. Adding additives during microwave heating process was helpful to improve the leaching rate of gold ...

Microwave heating has the effect of reducing the tempera-ture of chemical reaction. So it can avoid generating gases of SO2 and As2O3 by controlling the temperature appropri-ately.5–7) Kyuesi and Haque, etc. have studied the role of micro-wave in the gold extraction process of arsenic-bearing refractory gold ore.8,9) Haque K E used microwave ...

microwave heating of refractory minerals . The use of microwave heating for processing minerals is also not Get Price Advances in Induction and Microwave Heating of Mineral and tion and Microwave Heating of Mineral Materials and Part 2 Microwave Heating of .. The crucible is a cylindrical vessel made of a refractory material. Get . Chat Online