The effects of separate and combined usage of NaClO and KMnO₄ on the flotation separation of chalcopyrite and pyrite were investigated by performing flotation and adsorption tests, infrared spectroscopy (IR) and XPS analysis. The results show that selective separation of chalcopyrite and pyrite can be achieved with NaClO and KMnO₄ in a ratio of 10∶1, the total oxidant dosage of 70 mg/L, pulp pH of 10, and oxidation time of 3 min. It is shown that the recovery of chalcopyrite can exceed 92%, while the recovery of pyrite is less than 8%. The IR and XPS analyses show that a combined usage of NaClO and KMnO₄ obviously changes the surface property of pyrite, resulting in hydrophilic oxidized substances on the surface, such as iron oxide, iron hydroxide and iron sulfate, which impedes the adsorption of collectors, thus reducing floatability of pyrite. The chalcopyrite surface remains mildly inert to NaClO and KMnO₄ under certain conditions. Consequently, the adsorption of xanthate on chalcopyrite is remarkably higher than that on pyrite, which favors their flotation separation.

According to the mineral properties of a kind of flake graphite ore in Heilongjiang Province, a new efficient flotation reagent was developed and then adopted in a flotation experiment. Results show that with the new reagent of CYM-11 as a collector, CYQ-01 as a foaming agent, an experiment with a closed-circuit flowsheet consisting of eight-stage regrinding and nine-stage cleaning can yield an graphite concentrate with fixed carbon content of 96.63% at 95.69% recovery, among which the graphite concentrate at a size of +0.15 mm can be produced with a yield of 11.38% and fixed carbon content of 96.04% in mass fraction. It is shown that the large flake graphite can be well protected during the course of mineral processing.

To explore feasibility of replacing steel ball with porcelain ball in the second-stage grinding of a magnetite ore from Anhui, the feed ore to the second-stage grinding process in the magnetite ore processing plant was taken for study, and single-factor tests were conducted for gradation of porcelain ball in diameter, grinding concentration and filling rate of grinding media. On this basis, researches on grinding kinetics and commercial application were also conducted. The results show that porcelain ball can substitute steel ball as the medium in the second-stage grinding, which can bring in optimized particle size distribution of the milled product. For the feed in a particle size greater than 0.092 mm, the grinding rate of porcelain ball milling is greater than that of steel ball milling；while with the feed in a particle size less than 0.092 mm, the grinding rate of porcelain ball milling is less than that of steel ball milling. The best conditions for porcelain ball milling are finally determined as follows: porcelain balls with diameter of 30 mm, 25 mm and 20 mm in a mass ratio of 1∶3∶1, grinding concentration of 74% and grinding media with filling rate of 40%. The industrial applications with porcelain ball in mill shows the particle size distribution of overflow products can be effectively improved, both unit power consumption and ball consumption reduced by 51.89% and 50%, respectively.

Copper ore sorting by dual-energy X-ray technique basded on traditional algorithms by curve fitting of T-value always results in great deviation. In view of this problem, a curve fitting of T-value by segmented straight lines was proposed. This method divides thickness into several segments, and performs a T-value curve fitting in each segment for copper ore sorting, which can more accurately reflect the changing trend of T-value with different thicknesses and also reduce impact of thickness on sorting. High-energy and low-energy rays are adopted to fit the T-value curve, and then the residual between the T-value and the curve-fitting mapping value is calculated in each segment, showing different residuals for different substances, which can be used to achieve copper ore sorting. In a verification experiment, two types of copper ores with different grades were sorted by this method. The ore images fitted with T-value curves by segmented straight lines were put into ResNet18 neural network for training, and the trained model was then used for testing. The test results show that an accuracy rate can reach 88.67%.

An experimental study was performed on efficient separation of talc and molybdenite by adopting flash flotation. With grain fineness of 0.043-0.074 mm, 20 g/t of frother MIBC, and flotation time of 60 seconds, the talc recovery attains 76.64%, while the recovery of molybdenite is only 19.72%, resulting in an efficient separation between talc and molybdenite. According to the nonlinear fitting of flotation kinetic equation by MATLAB, talc flotation process conforms to the classic first-order flotation kinetic model, while molybdenite flotation conforms to the modified classic first-order flotation kinetic model. The following test on the influence of flotation time on adsorption of MIBC on talc and molybdenite shows that talc is more likely to interact with the agent than molybdenite at the early stage of flotation, and much more MIBC is adsorbed on talc than on molybdenite at that stage.

In order to utilize low-grade associated cassiterite resource from Huangshaping polymetallic ores, a new beneficiation process consisting of high-gradient magnetic separation (HGMS) for tailings discarding and tungsten-tin flotation for enhanced enrichment was developed based on the performed HGMS and flotation tests. After HGMS to pre-discard tailings, the loss rates of molybdenum, tungsten and fluorite were all less than 10%, while cassiterite was greatly enriched in the HGMS rough concentrates. Then, a flotation of reground HGMS rough concentrate was conducted by using Pb-BHA-SPA multiple ligand metal-based collector, producing a mixed tungsten-tin concentrate grading 0.627% WO₃ and 0.78% SnO₂, at corresponding recovery of 26.56% and 18.03%, respectively. This process provides a new idea and method for enhanced enrichment and effective utilization of low-grade associated cassiterite.

Based on the detailed process mineralogy study of a kind of refractory gold ore, an experimental research was carried out for gold extraction. It is found that the gold mineral in such ore are fine-grained and dispersed in gold-carrying minerals. It is proposed that such refractory gold ore be processed with the technique of enhanced flotation, and an addition of regulator XPT511 can effectively improve the index of gold flotation. It is shown that a close-circuit flotation test results in a gold concentrate grading 22.91 g/t Au at 62.85% recovery.

The chemical composition, types and content of minerals, microregion quantitative energy spectrum analysis of titanium-bearing minerals, equilibrium estimate of TiO₂, occurrence state of titanium-bearing minerals, particle size and dissociation degree of ilmenite in a vanadium-titanium magnetite ore from Panxi region have been investigated. By these means, the reasons for difficulty in this ore dressing were ascertained. The technical index of ilmenite concentrate and the main mineralogical factors affecting the ilmenite dressing effect have been analyzed comprehensively, which may provide a detailed scientific basis for development and utilization of this vanadium-titanium magnetite ore in Panxi region.

Copper slag flotation tailings were taken as raw materials, and carboxymethylcellulose (CMC), bentonite, sodium silicate alone or the mixture were taken as binders to prepare copper slag pellet for reducing dust and flue gas generated during utilization of copper slag tailings. The effect of binder on balling was explored in terms of the drop numbers, compressive strength and cracking temperature of green ball, and microscopic morphology, adsorption characteristics and surface potential changes were also analyzed by scanning electron microscopy, infrared spectroscopy and Zeta potential detection. Results show that all three binders can be useful in agglomeration of copper slag tailings. When used alone, CMC, bentonite and sodium silicate are required to be added at an amount more than 0.20%, 2.0% and 2.5%, respectively. In case of CMC used in combination with bentonite or sodium silicate, bentonite or sodium silicate should be added at an amount of more than 2.0% and more than 2.5%, respectively, with the addition of CMC is at an amount of 0.1%；while with the addition of CMC at an amount of 0.15%, the addition of bentonite or sodium silicate should be more than 1.5% and more than 2.0%, respectively. With the addition of binder, the prepared pellet has more compacted structure and stronger spatial structure. It is found that copper slag tailings particles have a lower value of zeta potential, and an improved hydrophilicity, which can promote interparticle adsorption, and thus improves pellet quality.

The acid leaching solution of cathode materials from spent lithium iron phosphate batteries was taken as raw material, and iron, phosphorus and lithium elements therein were recovered by adopting an oxidation-precipitation process. The effects of factors, including endpoint pH value of reaction system, reaction temperature, concentration of sodium hydroxide, dripping rate of sodium hydroxide, and the volume ratio of hydrogen peroxide to acid leaching solution, on the precipitation rates of iron and phosphorus and the loss of lithium during the precipitation process were all investigated. Results show that with the endpoint pH value of 2.5, temperature of 75 ℃, sodium hydroxide with concentration of 1.5 mol/L, sodium hydroxide solution at a dripping rate of 7.7 mL/min, and hydrogen peroxide and acid leaching solution in a volume ratio of 1∶60, the average precipitation rates of iron and phosphorus are 99.86% and 98.23%, respectively, and the average loss of lithium is just 1.23%. Under the above-mentioned conditions, iron and phosphorus in the solution can be effectively removed and recycled in the form of iron phosphate, presenting a lower loss rate of lithium. After 5 h-heat treatment at 700 ℃, it is shown that the chemical composition of iron phosphate can meet the industrial standard.