L D Michaud Enhanced gravity separation devices (centrifuges) have been patented for over a century but were impractical until recently. The physical laws behind the concept were well understood but engineering had to catch up with the science. This included the development of abrasion resistant materials, the improved design of rotating equipment that allowed higher RPM, and a … Read more
A number of compressive tests were conducted on iron ore pellets obtained from the Samarco pelletizing plant located at Ponta Ubu, Brazil. These pellets are formed by disk pelletizing of a mixture consisting of hematite iron ore, (particle size less than 50 µm) water, and lime; they are hardened in a traveling-grate furnace and the … Read more
Ff the drill cores indicate that the ore could contain sufficient lumps in the sizes needed for ore media in autogenous and semi-autogenous grinding, then bulk samples (750 kg) of mine run or primary crushed ore, with an even distribution by quantity in the size fractions between 100 mm and 200 mm, should be obtained … Read more
One of the minor but occasionally troublesome problems in the Creede plant is related to the clayey nature of some of the ore from the mine. At times the thickener underflow is so clayey that it forms a rope which can almost be carried around without a bucket. As described in the previous report: ” … Read more
Part of Zinc Hydrometallurgy and Zinc Solvent Extraction includes the zinc and iron sulphate solution from the hot acid leach will typically contain 80-100 g/l Zn, 20-30 g/l Fe, mostly in the ferric state, and 40-60 g/l free sulphuric acid. The sulphuric acid concentrations will depend upon the leaching techniques used, and the composition of … Read more
Alunite has been described both by the chemical formula [KAl3(SO4)2(OH)6] and by the chemical formula [K2SO4·Al2(SO4)3·2Al2O3·6H2O]. The latter gives an erroneous impression that water is structurally associated with the mineral. The former representation is therefore, to be preferred. It is more in conformity with the crystal structure of alunite. The structure of alunite is similar … Read more
Calculating Stockpile Capacity: Once the minimum storage capacities which will assure maximum mill output are known, the appropriate stockpile configuration must be determined. Stockpiles fall into two general categories: conical and elongated. Conical Stockpiles The conical stockpile is the simplest and easiest to analyze. The total stockpile capacity is given by: 3.14 (Tan A)R³ D/3000 = … Read more
Regrind Ball Mill F = 210 micrometers. P = 45 micrometers. Wi = 14.0 W = 10 x 14.0/√45 – 10 x 14.0/√210 = 11.21 kwh/s. ton Efficiency Factors: EF1 does not apply. EF2 Many regrind operations are closed circuit, but assume this one is open circuit and 80 percent passing grind will be … Read more