A process mineralogy study and mineral processing tests were conducted for a copper slag with Cu grade of 0.81%, and a beneficiation flowsheet for recovering copper resource and its technical parameters were determined. With Z-200 and 2^# oil respectively as collector and frother, the slag was processed after being milled to a fineness of -0.038 mm 85%, and a high-grade copper concentrate with Cu grade of 26.40% was collected by fast preferential floatation, while a low-grade copper concentrate with Cu grade of 3.58% was obtained from a subsequent flotation process consisting of one stage of roughing, two stages of scavenging and two stages of cleaning, resulting in the total copper concentrate grading 13.03% Cu at 76.47% recovery. This copper-recovering technique has been successfully applied in commercial practice, showing that the comprehensive utilization of Cu metal resource in a copper slag can be actualized.

The tailings of an iron mine in Baotou, Inner Mongolia, contain fluorite resources with large reserve and low CaF₂ grade. Unfortunately, the gangue minerals in the tailings, such as ankerite, calcite and barite, share similar floatability with fluorite, resulting in difficulty in fluorite recovery. With DKCS, FX-1 and starch introduced to depress ankerite, calcite and barite respectively, fluorite can be effectively separated from gangue minerals with modified oleate acid FH as the collector. It is shown that a closed-circuit test can result in a fluorite concentrate grading 90.68% CaF₂ at 64.69% recovery, showing a comprehensive recovery of fluorite resources from the tailings.

The dust generated during chlorination process in recovering titanium by metallurgical process was washed with water. Then, the residue left after water-washing was subjected to calcification roasting process, and the effects of roasting temperature and roasting time on the leaching rate of vanadium from the residue were studied. The results indicate that vanadium in the dust from chlorination process mainly exists as low-valent vanadium, and the vanadium leaching rate increases with the rising temperature. The vanadium leaching rate reaches 88% with the roasting temperature of 850 ℃. As the roasting time increases, the previously obtained different products undergo a secondary reaction, forming insoluble compounds of vanadium bronze, and also vanadate with different valences, which results in different vanadium leaching rates in Na₂CO₃ solution. It is concluded that the roasting process should be optimally at temperature of 850 ℃ with a roasting time of 120 minutes.

With orange residue extract and tetrasodium glutamate diacetate (GLDA) as raw materials, a green activator was prepared. Then, the effects of phosphate-solubilizing bacteria (PSB) combined with green activator on the enrichment, translocation and accumulation of cadmium from soil by ryegrass were studied. The results show that PSB can significantly promote the growth of ryegrass in cadmium-contaminated soil. However, the growth of ryegrass is inhibited by only using green activator, with the dry weight of ryegrass at the end of experiment decreased by 27.37%; while a combination of PSB and green activator can make the final dry weight of ryegrass become 1.29 times that in the blank group, indicating that the addition of PSB can alleviate the negative effect of green activator on the growth of ryegrass. A combination of both can increase the content of phytoavailable cadmium in soil, while decrease the total cadmium concentration in soil. It is shown that the enrichment coefficient of Cd in stem and root parts of ryegrass increases by 35.37% and 10.23%, respectively, and the translocation factor of cadmium by ryegrass increases by 22.58%. In addition, the total accumulation of cadmium in the stem and root parts of ryegrass is up by 87.90% and 32.69%, respectively. It is found that the total accumulation of cadmium in the stem is all greater than that in the root whether by using PSB and green activator separately, or by a combination of both, indicating that PSB combined with green activator can promote the phytoextraction efficiency of cadmium from soil by ryegrass.

The effects of the amount of NaFeS₂, which was used as an additive, on solid-state reduction and magnetic separation for enrichment of nickel and cobalt, and also the reduction behavior of nickel laterite ore were studied. The results show that with the increase of NaFeS₂ addition, the softening and melting temperature of nickel laterite ore decreases correspondingly during the reduction process; while particles of the Ni-Co-Fe alloy obtained by reduction increase accordingly. The enrichment and recovery effects of nickel and cobalt will be better by adding 10% NaFeS₂. The nickel laterite ore, after being pressed into briquettes, was subjected to reduction at 1 100 ℃ for 60 min, followed by a process of grinding and magnetic separation, resulting in a high quality nickel-cobalt-iron powder grading 7.89% Ni, 0.66% Co and 74.01% Fe, at corresponding recoveries of 97.13%, 86.78% and 35.81%.

In order to process copper complex wastewater from electroplating industry, a kind of kaolin was modified by using a modifier of 3-mercaptopropyl trimethoxysilane (MPTS) to be as an adsorbent, and its adsorption of E330-Cu was then studied. It is found that kaolin shall be properly modified at 50 ℃ for 6 hours with the modifier MPTS at an amount of 0.04 mL/g, which is then adopted as an adsorbent for E330-Cu. After 35 min- adsorption at 35 ℃, with E330-Cu at an initial concentration of 5 mg/L, adsorbent at an amount of 15 g/L, and pH value of 4.5, the final adsorption rate can reach 92.50%. It is shown that the adsorption process follows Langmuir isothermal adsorption model and quasi-second-order kinetic model. This kind of adsorbent can be repeatedly used for at least 3 times, and the wastewater after processing can meet the national classⅠdischarge standard. This research can provide reference for the treatment of copper-containing complex wastewater from electroplating industry.

The effects of excess coefficient of manganese fluoride, pH value of solution, reaction temperature and reaction time on the removal rate of calcium and magnesium from manganese sulfate solution were studied by performing single factor experiment with manganese fluoride as a removal agent. Under the optimum conditions, including an excess coefficient of manganese fluoride of 2.0, pH of 5, reaction temperature of 85 ℃ and reaction time of 80 min, the removal rates of calcium and magnesium can reach 97.06% and 95.48%, respectively. The kinetic study on this basis shows that the precipitation reactions of both calcium and magnesium in manganese sulfate solution conform to the Avrami equation, with apparent activation energies of 48.01 kJ/mol and 53.23 kJ/mol, respectively. The surface reaction is a factor to limit the precipitation rates of calcium and magnesium.

Acting as a raw material, mangosteen peel was subjected to decolorization with isopropanol and activation with alkaline reagent for preparing a kind of adsorbent, which was then used to adsorb copper ions in solution. The result from an adsorption experiment shows that increasing pH value can be beneficial to the adsorption of copper ions onto mangosteen peel, with the maximum adsorption capacity up to 1.5 molCu²⁺/kg. The adsorption can reach equilibrium within 30 min. The amount of loaded copper ions has a significant effect on the characteristic temperature of thermal decomposition of adsorbents during combustion. When the concentration of copper ions is lower than 2 mmol/L, there are higher number of loaded copper ions, and the temperature at which thermal decomposition begins and violent combustion decomposition ends becomes lower. When the concentration of copper ion is higher than 2 mmol/L, the characteristic value of thermal decomposition temperature no longer changes significantly. Copper ion plays a role of catalyst in the combustion process, which can effectively promote the combustion reaction.

An experiment of acid leaching was performed for the concentrate obtained by flotation pretreatment of a refractory sulphide ore. After leaching at 95 ℃ for 2 h, with nitric acid concentration at 9 mol/L, and liquid-solid ratio of 4∶1, the leaching rates of copper and zinc reach 90.46% and 85.34%, respectively, showing no lead leached out. The leaching process is mainly controlled by both solid film and chemical reaction.

A side blowing furnace was adopted to treat the leaching residue of copper anode slime and recover valuable metals therein comprehensively. The effects of soda dosage, granular coal dosage, precipitation time and top flue gas temperature on the recovery rates of main metals Pb, Sb, Bi, Au and Ag were investigated. The results show that with soda at an amount of 2.5%, granular coal at an amount of 3%, the precipitation time of 1.5 h, and the top flue gas temperature of 750 ℃, the precious lead product is obtained after processing, grading 1 544 g/t Au (1.84 times enrichment), 10.37% Ag (1.4 times enrichment), 22.89% Pb (2.1 times enrichment), and 27.45% Bi (2.2 times enrichment).