Wyniki wyszukiwania - BazTech

1

Gravity-based pre-concentration strategies for complex rare earth ore containing niobium and zirconium

Zhou Mingliang, Li Lixia, Liu Feifei, Liu Zhichao, Altun Naci Emre, Yuan Zhitao, Liu Jiongtian

Physicochemical Problems of Mineral Processing

|

2024

|

Vol. 60, iss. 1

art. no. 183609

EN

The Balzhe rare earth mine, renowned for its rich reservoirs of niobium, zirconium, and rare earth elements, poses a unique challenge due to its diverse and interbedded mineral composition. Despite the abundance of these elements, their valuable grade remains notably low, falling short of economic thresholds. To this end, pre-concentration of valuable minerals to discard gangue minerals before flotation would be an economical option. In response, this study delves into the feasibility of gravity-induced pre-concentration, aiming to segregate valuable minerals from gangue for subsequent flotation processes. Conducting float-and-sink tests on varied particle sizes (-2+0.5 mm, -0.5+0.074 mm, and -0.074+0.02 mm) within heavy liquids of specific gravities (ranging from 2.55 to 2.85), the study reveals the effectiveness of gravity separation. Notably, particles sized -2+0.5 mm and -0.074+0.02 mm demonstrated superior separation performance over the -0.5+0.074 mm fraction. Comparative analysis of diverse gravity separation equipment unveiled compelling results. The dense medium cyclone separator showcased impressive recovery rates and high-grade concentrates of Nb2O5, ZrO2, and total rare earth oxides (TREO) at 0.34%, 8.20%, and 0.41%, respectively, surpassing the sand table's performance for -2+0.5 mm particles. Conversely, for -0.5+0.074 mm particles, the shaking table exhibited optimal separation efficiency, yielding grades of Nb2O5, ZrO2, and TREO at 0.37%, 4.08%, and 0.44%, with substantial recovery values. Ultimately, the Knelson centrifugal separator proved most effective for -0.074+0.02 mm particles, yielding notable grades and recoveries of Nb2O5, ZrO2, and TREO. This study underscores the promising potential of gravity-induced pre-concentration techniques for enhancing the recovery of valuable elements from the complex Balzhe rare earth ore, offering critical insights into optimizing mineral extraction processes.

2

Selective leaching of copper from near infrared sensor-based preconcentrated copper ores

Ambo Amos Idzi, Iyakwari Shekwonyadu, Glass Hylke J

Physicochemical Problems of Mineral Processing

|

2020

|

Vol. 56, iss. 1

204--218

EN

Copper oxide ore was pre-concentrated using near infrared sensor-based method and classified as product, middling and waste. The product and middling fractions were leached with ammonium chloride reagent. The effect of temperature, ammonium chloride concentration, solid- liquid ratio, stirring speed and particle size experimental variables were investigated. Mineralogical and chemical analysis of the ore fractions indicated that copper content was in accordance with the preconcentration strategy, with the product having a higher concentration than the middling and waste. The rate of copper extraction was found to be higher in the product than in the middling sample which further supports the near infrared classification, QEMSCAN®, X-ray diffraction, SEM mineralogical and X-ray florescence and Inductively coupled plasma Mass spectrometry chemical data. It was revealed that the leaching rate increases with increasing ammonium chloride concentration, temperature and decreasing ore particle size, stirring speed and solid-liquid ratio. Analysis of the experimental data by shrinking core model indicated that the dissolution kinetics follow the heterogeneous reaction model for the chemical control mechanism where the activation energies of 45.9 kJ/mol and 47.5 kJ/mol for product and middling fractions respectively were obtained. Characterization of the residue obtained at optimum leaching condition with X-ray diffraction suggests that copper was selectively leached when compared to the profile of the raw ore. The trace levels of metals associated with abundant X-ray diffraction profiles of residue found in the leachate further confirm the selective leaching process.

3

Pre-concentration of graphite and LiCoO2 in spent lithium-ion batteries using enhanced gravity concentrator

Zhu X,-N., Tao Y.-J., He Y.-Q., Zhang Y., Sun Q.-X.

Physicochemical Problems of Mineral Processing

|

2018

|

Vol. 54, iss. 2

293--299

EN

The pre-concentration of electrode material of spent lithium-ion battery has great significance on the resource utilization and environmental protection. The feasibility of separation of graphite and LiCoO2 based on density difference using the enhanced gravity concentrator was verified in this paper. Combustion characteristics of LiCoO2 and graphite were used to propose a simple evaluation index of separation efficiency. Separation tests were carried out to specify the influence of operating parameters on the separation efficiency. Moreover, the effect of particle size on the separation performance was studied. Combustion characteristics results showed that mass loss of graphite was much greater than that of LiCoO2. Thus, mass loss were used to evaluate the purity of product. Effective separation of graphite and LiCoO2 was achieved by the enhanced centrifugal separator. Separation results showed that increasing centrifugal force decreased the overflow yield and increased the graphite content of the overflow stream. In addition, yield of overflow grew an increase in fluidization water pressure, while the purity of graphite in overflow decreased. The effect of particle size on the separation efficiency was also significant, the separation efficiency decreased with the decreasing of particle size.

4

Study on pre-concentration efficiency of wolframite from tungsten ore using gravity and magnetic separations

Lu D., Wang Y., Jiang T., Sun W., Hu Y.

Physicochemical Problems of Mineral Processing

|

2016

|

Vol. 52, iss. 2

718--728

EN

Pre-concentration is effectively applied in recovering wolframite from tungsten ore, due to its benefits of further upgrading tungsten ore and improving separation efficiency. The most important pre-concentration techniques for tungsten ore include gravity separation and magnetic separation, based on the fact that there are appreciable differences, between the desired wolframite and the gangue minerals, in density and magnetic susceptibility. This study investigated the separation efficiency of gravity pre-concentration (Falcon Concentrator) and high-gradient magnetic pre-concentration (SLon VPHGMS) for the beneficiation of a Canada tungsten ore. It is a low-grade type of ore with high silica and arsenic content, and an average content of WO3 is about 0.45%. The optimum conditions for different operational parameters of two pre-concentration separators were studied on this low-grade material. The results presented in this paper suggested that although both pre-concentration techniques were effective for producing pre-concentrates containing high WO3, magnetic pre-concentration showed significantly better separation efficiency. Over 90% of the feed was rejected as the final tailings, meanwhile, over 85% of arsenic minerals were removed with tailings, while the WO3 loss was less than 15%.