For the Lihir gold ore, a decrease of 11% in the comparative grindability was obtained when it was exposed to 1500W microwave energy for 8 minutes. The decrease in grinding resistance resulted predominantly from the fractures induced by thermal stresses and differential thermal expansion of mineral phases during microwave heating.
Recently, the effect of microwave pretreatment on the grindability and leachability of a free-milling gold ore containing quartz, silicates and iron oxides was examined. 173 As shown in Fig. 22a ...
Dec 10, 2013· The present paper attempts to assess the effects of microwave irradiation on the leachability of refractory gold ores. Characteristics of the crystal structure and microstructure of the ores were determined by x-ray structural analysis (XRD) and scanning electron microscopy (SEM) before and after microwave irradiation. Compared to conventional processes, microwave leaching processes …
Improved grindability and gold liberation by microwave pretreatment of a free-milling gold ore R.K. Amankwah, A.U. Khan, C.A. Pickles & W.T. Yen Pages: 30-36
The influence of microwave treatment on the liberation of iron ore from the high phosphorus oolitic iron ore from Aswan region, Egypt was studied. The effect of microwave power, exposure time and grain size on the liberation of iron ore was investigated. The microfractures and cracks of the samples were characterized before and after microwave treatments.
Preliminary research on grindability improvement of coal by microwave pretreatment 645 study the comminution characteristics of different minerals to improve the efficiency of crushing (Ito et al., 2009; Xiao et al., 2012; Wang et al., 2012). Microwave radiation is …
Amankwah used microwave processing to treat gold ore, which increased the liberation of gold, and gold recovery improved from about 28%–40% . High-phosphorus oolitic hematite is usually associated with hematite, carbonate-hydroxyapatite, quartz and chamosite, which have different abilities in absorbing microwave energy and dielectric ...
Improved grindability and gold liberation by microwave pretreatment of a free-milling gold ore. ... Improved grindability and gold liberation by microwave pretreatment of a free-milling gold ore.
Feb 01, 2011· Microwave-derived reductions in grinding energy lead to increased mill capacity and reduced wear, better control of mill product size and improved liberation, alteration of the physicochemical properties of ground products, lower water consumption and a …
The relationship between heating rate and surrounding environment is also discussed in this study. Investigations indicated that the microwave exposure could reduce the grindability of ores. For the Lihir gold ore, a decrease of 11% in the comparative grindability was obtained when it was exposed to 1500W microwave energy for 8 minutes.
May 01, 2011· Research highlights Microwave heating of a material leads to micro-crack formation. Micro-crack formation allows size reduction and liberation at a lower stress level. Micro-cracks generated enhances access of lixiviants to the mineral of interest. Microwave processing enhanced grindability and cyanide amenability of the gold ore.
Feb 05, 2014· Microwave heating responses of bauxite and sawdust were determined as a function of mass and time, and both materials proved to be active microwave absorbers as they heated rapidly. ... Improved grindability and gold liberation by microwave pretreatment of a free-milling gold ore. Mineral Processing and Extractive Metallurgy, IMM, Transactions ...
Improved grindability and gold liberation by microwave pretreatment of a free-milling gold ore R.K. Amankwah, A.U. Khan, C.A. Pickles & W.T. Yen Pages: 30-36
Preliminary research on grindability improvement of coal by microwave pretreatment 645 study the comminution characteristics of different minerals to improve the efficiency of crushing (Ito et al., 2009; Xiao et al., 2012; Wang et al., 2012). Microwave radiation is …
Improved values of grindability were obtained at all temperatures tested which confirmed the hypothesis that microwave energy can induce thermal stress cracking. Of greater importance was the improvement in grindability at low bulk temperatures in comparison to the …
A similar investigation by Amankwah et al. [75] on improved grindability and gold liberation by microwave pre-treatment of a free-milling gold ore also verified the above findings. ...
The effect of microwave treatment on the grinding kinetics of an iron ore was assessed using mono-sized materials of −2.360 + 2.0 mm, −1.400 + 1.180 mm, −1.0 + 0.850 mm, and −0.355 + 0.300 mm as feed. Microwave-treated samples were kept in a multimode microwave oven with 1100 W input power.
However, this was improved after the head ores or floatation concentrates were pretreated by microwave radiation. 74.581.2% of the gold was extracted from the microwave treated head ore. The hydrometallurgical pretreatment of pyrite and marcasite in a microwave field and a conventional heating environment was also investigated.I,n a nitric acid ...
The findings of the literature review revealed that microwave heating can improve the liberation, grindability, and magnetic separation of valuable minerals from ores and has the potential to ...
Grindability tests indicated that microwave treated iron ore could be more easily ground compared with iron ore treated in a conventional furnace. This improved grindability is attributable to the large amount of intergranular fractures which are formed on the oolitic iron ore after treatment with microwave …
Amankwah, R K, Khan, A U, Pickles, C A and Yen, W T (2005), "Improved grindability and gold liberation by microwave pretreatment of a free-milling gold ore", Mineral Processing and Extractive Metallurgy, IMM, Transactions C, 114, C30-C36.
The grindability of ore with consistent texture (OK ore) improved dramatically with microwave treatment, whereas the grindability of ore with inconsistent texture (Pipe ore) was found to decrease. Pentlandite liberation and specific surface area improved for both ores with microwave treatment.