Flotation tests were conducted for a complex refractory copper-lead-zinc polymetallic sulfide ore bearing arsenic and silver. By using a new high-efficient sulfide ore collector (CYC) and an environment friendly lead depressant (CYZ), the test with a flowsheet consisting of rough grinding, copper-lead-silver bulk flotation, classification and regrinding, reagent removal and Cu/Pb separation produced a copper concentrate grading 22.42% Cu and 11 549.74 g/t Ag with corresponding recoveries of 73.77% Cu and 83.85% Ag, as well as a lead concentrate grading 13.96% Pb and 6.61% Sb with corresponding recoveries of 19.45% Pb and 11.10% Sb. It is shown that with this technique, an efficient Cu/Pb separation can be actualized, while the associated Ag and Sb minerals can also be reclaimed effectively.

Blown zinc powder, electric furnace zinc powder, zinc alloy powder and distilled zinc powder were respectively taken in the test of cobalt removal by arsenic trioxide purification process to investigate influences of several factors on cobalt removal effect, including an adding amount of zinc powder, temperature and time of reaction, a mole ratio of copper to cobalt and a mole ratio of antimony to cobalt. Results show that when copper sulfate is added with copper and cobalt in a mole ratio of 5.0, potassium antimony tartrate is added with antimony and cobalt in a mole ratio of 0.5, a reaction at 90 ℃ for 90 min, with rotation speed of 300 r/min and addition of zinc powder at an amount of 2 g/L, the cobalt removal rates by using 4 different kinds of zinc powder are 95.73%, 96.15%, 95.94% and 94.87%, respectively, indicating the cobalt removal effect of different powder in the following descending order: electric furnace zinc powder > zinc alloy powder > blown zinc powder > distilled zinc powder.

An efficient defluorination agent (NY-Z02) was used to remove fluoride from high-salt fluoride-containing wastewater generated in the process of recycling spent batteries. The effects of pH value, reaction temperature, reaction time and dosage of defluorination agent on fluoride removal effect were investigated. On this basis, a two-stage fluoride removal process was put forward, with which a pilot test was carried out. Results show that by using a single-stage fluoride removal process, a reaction runs at 20 ℃ for 20 min with pH of 7.0 at the end and by adding defluorination agent at an amount of 1.2%, resulting in the fluoride concentration in the wastewater decreased to 12.5 mg/L. While by using a two-stage fluoride removal process, with addition of defluorination agent at an amount of 1.0%, the fluoride concentration in the wastewater can be decreased to 12.4 mg/L. In the pilot test with the dosage of defluorination agent reduced to 0.768%, the fluoride concentration in the wastewater after fluoride removal process met the requirement of enterprise (F≤20 mg/L). It is found that during the removal process with agent NY-Z02, fluoride ions in wastewater react with the agent and form precipitate of AlF₃, or together with Al (OH)₃ are removed by flocculation and precipitation. It is shown that this process has good fluoride removal effect without bringing in any impurities.

With support vector machine (SVM) optimized by whale optimization algorithm (WOA), a WOA-SVM hybrid model was established for predicting blasting vibration. Then, with root mean squared error and coefficient of determination as evaluation indices of the model, WOA-SVM model, SVM mode, Sadovsky's model and USBM model were compared based on the data of blasting vibration in Sijiaying Iron Mine. A comprehensive evaluation shows that the WOA-SVM model is superior to other models in terms of prediction accuracy.

A commercially applied large ball mill with an effective internal diameter of 4.6 m is taken for study, and the discrete element method (DEM) was introduced to simulate and investigate the influence of filling rate of grinding media (steel balls) on the collision of particles inside the mill and energy consumption. It is found that when the filling rate of grinding media is 30% - 35%, the frequency of ball-ore collision increases gradually. However, the ratio of ore-ore collision frequency to the total collision frequency increases first and then decreases, and the energy loss for ball-ball and ball-liner collisions increases. It can be seen that increasing filling rate of grinding media may not only reduce grinding efficiency and increase energy loss, but also increase liner wear by steel ball, which is not conducive to sustainable usage of mill liner.

In order to accurately evaluate stability of surrounding rock of roadway with weak intercalation, an improved analytic hierarchy process and criteria importance through inter-criteria correlation (CRITIC) method, were adopted to determine comprehensive weight, and unascertained measure theory (UM) was used to determine unascertained measurement vector. Furthermore, the set pair analysis theory (SPA) was introduced to optimize confidence evaluation process, and then a UM-SPA coupling analysis model was established and used to evaluate the stability of surrounding rock of the roadway with weak intercalation in some gold mine. The results show that in-situ stress, tensile strength and thickness of weak intercalation are the main factors influencing the stability of such kind of roadway. The set pair potentials of sections D4, D5, D6, D7, and D9 belong to micro-reversal potential and tend to be unsafe. The stability of roadway at different levels is in the following descending order: 290^# level > 150^# level > 90^# level. The practical verification has proven that this model has an evaluation result consistent with the actual situation.

A barite ore from Guizhou province is a typical microfine refractory carbon-containing ore with uneven grain size distribution and complex dissemination relationship among barite and gangue minerals. After being milled to a grinding fineness of -0.075 mm 90%, the ore was processed using kerosene and terpenic oil for decarburization, with sodium carbonate as the pH regulator, sodium silicate as the depressant and CY-30 as the collector for barite flotation. A close-circuit flotation test yielded 75.92% barite concentrate grading 93.55% BaSO₄ at 87.85% recovery.

Experiments of erosion corrosion with 3.5% NaCl solution at different flow rates were performed for TP2 copper after different heat treatment (hard and soft states), and the erosion corrosion rates of TP2 copper were tested. The morphology and products after 240 hours of corrosion were characterized, and the mechanism of erosion and corrosion for TP2 copper was also discussed. The results show that flowing medium in corrosion test accelerates the corrosion rate of TP2 copper. The soft TP2 copper presents a higher corrosion rate, compared to hard TP2 copper, after 240 hours of corrosion at the same flow rate. And after 240 hours of erosion corrosion at a higher flow rate, TP2 copper has its surface morphology predominated by gully-like structure and a product of Cu₂O is generated after corrosion.

Flotation tests were carried out for a low-grade complex copper ore from Hubei province. The influences of grinding fineness, reagent type and dosage on flotation indices were investigated. A closed-circuit flotation flowsheet consisting of one stage of roughing, three stages of cleaning and three stages of scavenging was adopted to process this kind of ore with Cu grade of feed ore of 0.42%, grinding fineness of -0.074 mm 75.2%, butyl xanthate combined with Z-200 and sodium diethyldithiocarbamate as collectors, calcium hypochlorite combined with lime as regulator. As a result, a copper concentrate with Cu grade of 12.15% and recovery of 85.05% was recovered.

In order to solve the problem of high water content in JISCO iron concentrate, dewatering tests were conducted by adding filtration aid. The results show that the filtration aid, CYG-1, can improve filtration effect. With the addition of CYG-1 at an amount of 500 g/t, the water content in the filter cake of iron concentrate falls by 2.31 percentage points compared to the practice without adding filtration aid.