Aiming at the problems of accuracy in prediction of ore grade and recovery in dry magnetic separation process, a prediction model framework integrating XGBoost and Transformer was proposed. In this method, XGBoost is used to extract local features and enhance features via leaf node information, improving the representation ability of input data. Subsequently, Transformer employs a multi-head self-attention mechanism to explore global dependencies among features and strengthen the prediction performance of the model. The prediction results of dry magnetic separation of ilmenite show that the constructed integrated model outperforms SVR, XGBoost, BP neural network and standard Transformer in terms of prediction accuracy and generalization ability.

Beneficiation tests were conducted on a high-talc complex copper-molybdenum ore. Two process schemes were explored, including pre-flotation for talc removal and direct talc depression. The results show that partial talc can be removed by pre-flotation with tap water, and pre-flotation with plant recycling water leads to high loss rates of copper and molybdenum in froth products, failing to separate easily floatable gangue minerals from copper-molybdenum minerals. By adopting a new depressant TCM-596 for direct talc depression in flotation with recycling water, a closed-circuit test produced a copper-molybdenum bulk concentrate with Cu recovery of 81.60%, Mo recovery of 63.95%, and MgO content of 2.43%. This indicates that talc is depressed and effectively separated from copper-molybdenum minerals, actualizing efficient enrichment of the high-talc copper-molybdenum ore.

To enhance the economic benefits of a silver-lead polymetallic ore concentrator in Henan Province, a systematic study was conducted on flotation process optimization and reagent system innovation based on the analysis of silver occurrence state and the paragenetic relationship among carrier minerals through process mineralogy. The research outcomes demonstrate that by implementing a process flow consisting of two roughers, three cleaners and three scavengers, and substituting the conventional sodium sulfide with a composite depressant system consisting of sodium silicate and CMC (carboxymethyl cellulose), the industrial production operates stably and continuously. As a result, the quality of lead concentrate is significantly improved, and the pricing coefficients of associated metallic elements are also enhanced simultaneously. The lead concentrate is obtained with Ag grade of 14 876.15 g/t at recovery of 87.77%, and Pb grade of 15.28% at recovery of 73.34%. Compared to the original reagent system, the Ag grade of the concentrate increases by about 4 923 g/t, while the recovery decreased slightly by 0.80 percentage points. The Pb grade of the concentrate increases by 5.05 percentage points and the corresponding recovery increases by 1.93 percentage points.

To achieve economical and efficient recovery of iron from the vanadium-titanium magnetite ore resources in a typical mining area of Panxi, a systematical process mineralogy analysis was conducted for representative and comprehensive ore samples from this area. On this basis, experimental studies were carried out, including pretreatment of coarse ore for tailings discarding, staged grinding and low-intensity magnetic separation (LIMS) processes. The results show that iron in the ore mainly occurs in titanomagnetite, which has a complex dissemination with ilmenite and gangue minerals. Moreover, exsolution textures such as fine-grained ilmenite lamellae are widely developed in titanomagnetite, which is the key factor restricting the improvement of iron concentrate grade. The comprehensive ore sample was processed by adopting a process of wet pre-discarding, three-stage staged grinding and three-stage LIMS, and an iron concentrate grading 57.98% TFe was obtained with a TFe recovery of 61.99%.

An experiment was carried out for separating copper and molybdenum in a porphyry copper ore by adopting ALC mill in combination with a micro-bubble flotation machine. Firstly, the raw ore was ground with ALC mill to a P₈₀ 47 μm, and then subjected to a closed-circuit flotation consisting of one roughing, two cleaning and one scavenging with an appropriate reagent system, leading to the obtained molybdenum concentrate grading 47.25% Mo and containing 1.29% Cu, with recovery of 63.04% Mo. It is shown that a satisfactory separation of copper and molybdenum is actualized.

To improve mineral processing performance, experimental tests were carried out on the lead-zinc ore from Henan Province by adopting stepped flotation process, consisting of Pb-S bulk flotation, Pb/S separation, zinc sulfide flotation, lead oxide flotation and zinc oxide flotation. A small-scale closed-circuit test produced five products, including qualified lead concentrate, zinc concentrate, sulfur concentrate, lead oxide concentrate and zinc oxide concentrate. The recommended flowsheet was applied into industrial trial production, and satisfactory processing indicators were achieved. It is shown that the utilization rate of mineral resources can be greatly improved by adopting this technique.

SY-MOF-1 composites with distinctive structures and properties were successfully synthesized using precursors containing hydroxyl, carboxyl, amino and other functional groups. The effects of SY-MOF-1 composites with different functional groups on lead removal from soil were investigated. The results reveal that surface functional groups, specific surface area and pore structure of the functionalized all composites all change remarkably, providing abundant adsorption sites for lead ions. The functionalized SY-MOF-1 composites were used in the remediation of lead-contaminated soil, and the optimal adsorption conditions were determined as follows:solution pH of 6, reaction temperature of 25 ℃ and reaction time of 20 min. It is found that under such conditions, SY-MOF-1-AMP presents a higher adsorption capacity for lead in soil, reaching 146.5 mg/g. The adsorption process of lead onto functionalized SY-MOF-1 composites conforms to the pseudo-second-order kinetic model and Langmuir isothermal adsorption model, indicating that the adsorption is dominated by chemical adsorption and features monolayer adsorption. The functionalized SY-MOF-1 composites exhibit excellent performance in the remediation of lead-contaminated soil. It can serve as an efficient material and a feasible technical route for the treatment of lead-polluted soil, thus possessing promising application prospects.

A novel processing technique for efficient arsenic removal by collaborative roasting of low-grade tin middlings and lead smelting flue dust is proposed in this study. It is shown that FeAsS, the arsenic-bearing phase in tin middlings, decomposes into elemental As and FeS during roasting. These decomposition products can reduce arsenate phases in lead smelting flue dust into volatile As₂O₃, thereby realizing high-efficiency arsenic removal. With an addition of lead smelting flue dust at an amount of 30%, roasting at 700 ℃ for 90 min can lead to the arsenic removal rate reaching 94.73%.

Mn₃O₄ for lithium-ion batteries was synthesized by suspension oxidation using metallic manganese powder. The effects of experimental conditions, including ammonium chloride concentration, ammonia concentration, solid-liquid ratio, reaction temperature, air flow rate and stirring speed, on the particle size and tap density of Mn₃O₄ were investigated. The results show that under the optimal conditions, including ammonium chloride concentration of 6 g/L, solid-liquid ratio of 0.3∶1, reaction temperature of 70 ℃, air flow rate of 700 mL/min, and stirring speed of 400 r/min, the as-prepared product is spinel-type Mn₃O₄ with quasi-spherical particles, which has a D₅₀ particle size of 9.69 μm, tap density of 2.82 g/cm³, specific surface area of 0.399 m²/g, and manganese content of 71.5%. The contents of impurity elements such as S, Fe and Ca therein all meet the requirements in Manganese Tetroxide for Lithium Batteries (YB/T 4736—2019).

In accordance with GB/T 20899.1-2019, a mathematical model was established to analyze and calculate uncertainties from various sources in determining gold content in gold ores by fire assay combined with atomic absorption spectroscopy. Based on the combined calculation, it is shown that when the gold content of the ore samples is 2.28 g/t, the standard uncertainty of this method is 0.04 g/t, and with a coverage factor k=2, the expanded uncertainty is 0.08 g/t. Comparison of uncertainty contributions indicates that repeatability of sample measurement and standard curve fitting are the major influencing factors. Therefore, it is recommended that measuring instruments should be kept in optimal condition, and the number of replicate measurements be increased to reduce measurement uncertainty.