The South African gold mining industry has a legacy of abundant tailings dams, which have attracted the attention investors because their potential as cheaper secondary resource. In this we investigate study recovery from refractory calcine dam. Bulk mineralogy indicated silicates and iron oxides to be most phases. Scanning Electron Microscopy (SEM) showed exist in submicrometre micrometre size...

The roasting of chalcopyrite, the most exploited copper mineral, presents a very important step in the copper extraction during the traditional smelting-refining process, as well as in advanced processes in copper metalurgy 1-2 . Consequently, numerous researches have been investigated, in order to study the chalcopyrite oxidative roasting parameters, its mechanism and reactions involved 1-16 ....

sesame (sesamum indicum l.) seed and oil have long been used widely as healthy foods to supply energy and prevent aging. some of the main active anti-oxidative constituents in sesame seeds are γ-tocopherol and phenols. the purpose of this study was to investigate the relationship between roasting temperature and time with γ-tocopherol and total phenolic compounds (tpc) of sesame seeds when roas...

Gourd seeds have been identified as a source of edible oil, but there is sparse literature on the effect of processing factors on the characteristics of oil extracted from any Lagenaria spp. Optimization of oil extraction with the aid of expeller was achieved by applying response surface methodology. The variables were roasting temperature (87.70-172.0°C) and roasting duration (7.93-22.07 min),...

Recovery of zinc from low grade zinc oxide ore is attempted with ammonia and ammonium citrate solutions augmented by microwave roasting and ultrasound radiation. The influence of the ammonia-ammonium ratio, roasting temperature, ultrasound power, and leaching time were assessed on the recovery of zinc. A maximum zinc recovery of 88.57% could be achieved at a roasting temperature of 673 K, leach...

The effect of heat treatments (boiling, autoclaving, microwave cooking and roasting) on the levels of certain antinutritional factors (phytic acid, trypsin inhibitor, α-amylase inhibitor, lectin activity and tannins) and in vitro protein digestibility (IVPD) of peanut and sesame seeds were investigated. All heat treatments significantly reduced the levels of all the investigated antinutrients a...

A metal-chelating substance in brewed coffee was separated and characterized by its chemical structure. This substance was a brown polymer. The contents of sugars, amino acids and phenolics in the substance were evaluated. This polymer contained small amounts of sugars and amino acids in its partial structure. After being decomposed by alkaline fusion, the decomposition products were identified...

We investigated the effect of various cooking methods (boiling, steaming, stir-frying, and roasting) and three cooking times (5, 10, and 15 min) on the antioxidant properties of red pepper. Raw and cooked peppers were measured for proximate composition, ascorbic acid (AsA) content, total carotenoid content (TCC), total polyphenol content (TP), and 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-a...

In this study, the effect of temperature (140, 160, 180 °C) and roasting time (5, 10, 15 min) on the bioactive compound content (canolol, tocopherol and plastochromanol-8) of cold-pressed oil from yellow-seeded rapeseed lines of different colors was investigated. Roasting increased the peroxide value in the seed oils compared to the oils from the control samples. However, roasting did not affec...

The residue from desulfurization and denitrification of exhaust gas treatment process with pyrolusite ore as absorbent is regarded as a potential source of iron and manganese. In this study, an extraction process is proposed for recovery of iron and manganese with ammonium sulphate roasting followed by sulphuric acid leaching. Firstly, the conversion mechanism was analyzed through mineral phase...