Process Mineralogy Characteristics and Flotation Application of a Refractory Collophanite from Guizhou, China

A refractory phosphate ore obtained from Guizhou, China, contains high amounts of detrimental metal impurities (e.g., Fe, Al, and Mg) which affect the deep wet processing of phosphorus products before use. In this study, mineralogy parameters of the ore such as mineral composition, disseminated particle size, mineral liberation degree, and intergrowth relationship were investigated using X-ray fluorescence spectrometer (XRF), X-ray powder diffractometer (XRD), and advanced mineral identification and characterization system (AMICS). The mechanism for flotation separation was also discussed. The results showed that the ore was a fine-grained calcareous-siliceous collophanite with high P2O5 grade. The gangue minerals such as quartz, sericite (muscovite), pyrite, and dolomite were finely disseminated and encapsulated by fluoroapatite particles in a rather complex relationship. A double reverse flotation process was carried out based on the separation principle of less flotation and more inhibition. A phosphorous concentrate with a P2O5 grade of 35.53%, SiO2 content of 5.88%, MgO content of 0.91%, sesquioxide (Fe2O3+Al2O3) content of 1.98%, MER value of 8.13%, and phosphorus recovery of 75.04% was obtained. Based on the flotation test results and the analysis of process mineralogy parameters, we concluded that the main causes of difficulty in separation of collophanite are fine disseminated particle size, poor mineral liberation degree, and serious argillization. The selection of foam-controlled collectors, efficient dispersing inhibitors and classified desliming process will be necessary for improving flotation index. These results provide a technical reference for subsequent development and utilization of collophanite resources.

Study on process mineralogy of limonite

In this paper, the process mineralogy, such as the composition and content of elements and minerals, and the chemical composition of main minerals, was studied by the method of mineral liberation analyser. The results show that the ore is limonite bearing-zinc ore, the content of the main mineral limonite is 95.982%, most of limonite is monomeric, a few limonite is associated with pyrite and muscovite, with quartz, with sericite and quartz, limonite contains sericite, synbiote of limonite and sericite. Zinc occurs mainly in limonite, a small amount of zinc in the form of sphalerite, smithsonite and hemimorphite. This study will lay a mineralogical foundation for the follow-up development and utilization of this type of ore.

Characterization of amalgamation tailings from ASGM in Sekotong area, West Nusa Tenggara, Indonesia, and its potential added value

Artisanal and small-scale gold mining (ASGM) in Indonesia still uses mercury in amalgamation process to extract gold form the ores. The process easily produces gold but at the same time produces very dangerous mercury waste. In this study, a comprehensive series of tests were carried out on amalgamation tailings from the ASGM in Sekotong area, West Nusa Tenggara. The tailings contain mercury up to 150 ppm, above the safe threshold, and gold up to 20 ppm which is intended to be recovered. Furthermore, mineral liberation analysis (MLA) and gravity recoverable gold (GRG) test were performed to determine the feasibility of recovering gold from the tailings. The liberation degree of the gold started from particle size of 37 \xm causes challenging to recover it. However, the GRG test confirmed that the gold was still feasible to be recovered by gravity concentration.

Assessing the Grindability Behaviour of Anka (Zamfara State, Nigeria) Manganese Ore towards Effective Manganese Mineral Liberation

The Bond standard grindability test provides a Work Index that is widely used to estimate the energy required for ore grinding. The research investigates the work index of Anka Manganese ore at Anka deposit in Zamfara state, Nigeria. The reference ore (Quartz) was sourced from the studied ore overburden in the mine. The test ore and the reference ore were characterized using Energy Dispersive X-ray fluorescence spectrometer, X - ray Diffractometer and the Scanning Electron Microscope equipped with Energy Dispersive Spectrum. 500 g each of the manganese ore and quartz were sampled and prepared by crushing and grinding to 100% passing 1200 μm sieve. 100 g of prepared ores were charged into array of sieve arranged in √2 series from 1000 μm to 63 μm. Set of sieves were mounted on the Automated Pascal Denver sieve shaker (16153) and was in operation for 20 minutes. The work index of reference ore was used to calculate the work index of the test ore using Gaudin Schuman expression to obtain a work index of 14.16 Kwh/ton for test ore and it lies within the work index of 10-15.14 Kwh/ton for manganese ore stated in the literature and the energy expended to achieve communition at mineral liberation size was calculated to be 3.3984 Kw/ton.

Mineral Liberation: A Case Study for Buzwagi Gold Mine

Buzwagi Gold Mine (BGM) process plant was designed such that, after secondary grinding, gold and copper are recovered by flotation. However, the flotation circuit had been inefficient, and as a result, cyanidation of flotation tailings is currently conducted to improve gold recovery. The inefficient flotation is suspected to be due to mineralogical variations of ores treated. Hence, mineral liberation characteristics of three ore blends treated by BGM were investigated by automated Scanning Electron Microscope (SEM) whereby five fractions (i.e. -1 +0.5 mm, -0.5 +0.25 mm, -0.25 +0.125 mm, -0.125 +0.063 mm and -0.063 mm) were used. It was found that pyrite-pyrrhotite is the major valuable phase and the host of gold. Furthermore, pyrite-pyrrhotite was liberated at relatively coarse size (i.e. approx. 200-400 µm). Additionally, quartz, feldspar, muscovite and biotite-chlorite were the main gangue phases. Pyrite-pyrrhotite grain size distribution was coarser than most gangue minerals in the ore blends, indicating that most of the milling energy was lost in grinding of gangue phases. Since gold host phase (pyrite-pyrrhotite) was liberated at coarser sizes, it was concluded that the efficiency of gravity circuit could not be affected. However, the flotation process will still require finer feed (i.e. ≤ 125 µm) for its efficiency. Keywords: Mineral liberation; Gold ore blends; Flotation Performance; Pyrite-pyrrhotite; Automated Mineralogy