金川集团股份有限公司

To elucidate the mineralization process of the No.3 orebody of the Jinchuan deposit and to refine the Jinchuan metallogenic model,it conducted EPMA of ore minerals together with whole-rock major-trace element and Ni-Cu-PGE analyses.Olivine from the fine-grained and pegmatitic lherzolite hosting the No.3 orebody shows Fo values of 82.4%-85.0%and Ni contents of 1 069×10⁻⁶-2 420×10⁻⁶.Both Fo and olivine Ni content increase progressively from the northwest to the southeast.Major-element variations suggest that the No.3 orebody experienced dominantly olivine-and pyroxene-controlled fractional crystallization.The ore-bearing rocks are slightly enriched in light rare earth elements(LREE),markedly enriched in large-ion lithophile elements(LILE),and depleted in high-field-strength elements(HFSE).The total PGE abundances of the No.3 orebody are comparable to those of the No.24 orebody,but are significantly higher than those of the No.1 and No.2 orebodies.Importantly,the southeastern segment of the No.3 orebody remains relatively more mafic and therefore retains greater mineralization potential.These observations support a metallogenic model in which the Jinchuan deposit formed through"mantle-derived magma,sulfide segregation,and multi-center emplacement of mineralized magma".The No.3 and No.24 orebodies were supplied by the same magma conduit,whereas the No.1 and No.2 orebodies were fed by separate conduits.

Named Entity Recognition(NER)is a fundamental task in building knowledge graphs and directly affects graph quality.However,in practice,mechanical failure data often contain a significant amount of domain-specific vocabulary,and in general,an imbalance exists in the distribution of entity types.Thus,existing NER methods in general domains do not yield satisfactory results.To address these problems,this paper proposes an entity recognition method that integrates a Focal Loss function into domain-specific dictionaries.This method improves the cross-entropy loss function by introducing balancing and modulation coefficients for sample distributions.In addition,entity recognition is enhanced through the fusion of vocabulary features.Experimental results on a self-built dataset of mining hoist machines show that the incorporation of Focal Loss increases the F1 value by 5.57 percentage points compared with the mainstream Bidirectional Encoder Representations from Transformers(BERT)-Bidirectional Long-Short-Term Memory(BiLSTM)-Conditional Random Field(CRF)model.Furthermore,it outperforms the typical Synthetic Minority Over-sampling Technique(SMOTE)method in solving imbalanced data issues.By incorporating domain dictionaries,the F1 value is further improved,reaching 89.13％.

Coarse aggregate paste filling is the core direction of today’s mine development. The coarse aggregate filling can effectively reduce the discharge of the solid mine waste, which is conducive to the realization of safe, clean, and efficient mining of the deposit and can also reduce the production costs of infill mining and promote the coordinated development of green mining. To study the pipeline conveying characteristics of the tailing‒waste rock paste, the rheological properties were tested by a rheometer under different tailing‒waste rock ratios and solid content conditions. A resistance equation integrating the compactness, water‒cement ratio, and volume concentration was constructed. This was then brought into the Comsol software for simulations and compared with the actual measurement results of the ring pipe. Errors measured by the numerical model are verified to be all within 7%, indicating that the model reasonably calculated the resistance characteristics of the tailing-waste rock paste. Variation characteristics of the pipeline conveying resistance under different solid contents, tailing‒waste rock ratios, and initial velocity conditions were also simulated. Experimental results show that the plastic viscosity and yield stress increase with the solid content and tailing‒waste rock ratio. Due to the friction effect between the particles, the resistance loss tends to increase and then decrease with the tailing‒waste rock ratio. The increase in the solid content leads to a decrease in the water content of the paste, which consequently results in difficulty in the flow of coarse aggregate slurry and a rapid increase in the resistance loss. The initial flow rate increases, the particle motion becomes unstable, the friction increases, and the growth rate of the drag loss increases greatly after the “inflection point” of 2.2 m·s−1. It is recommended that the mine should be filled with a tailing‒waste rock ratio of 5∶5 and an initial flow rate of 2.2 m·s−1. The results have certain reference significance for the design of a coarse aggregate paste pipeline conveying system, which helps the development of coarse aggregate paste conveying technology and also has a positive effect on reducing the pipeline conveying resistance and extending the conveying distance.

Biodegradable mulch has become a substitute for polyethylene non-degradable mulch in sustainable agriculture. Compared with the traditional polyethylene film, the biodegradable film has the defects of poor water vapor barrier property, low mechanical strength and difficult control of degradation cycle. The research progress of biodegradable mulch film in improving mechanical properties and barrier properties is reviewed. The application effect of biodegradable mulch film in laying crops in short and medium growth cycle is introduced. Combined with the current research and application of biodegradable mulch, some suggestions on the research and application of biodegradable mulch were put forward and the future development trend is prospected.