To investigate the effect of vertical isolation columns on the stability of surrounding rock during the deep mining of gently inclined thick ore bodies, a numerical simulation method was used to compare and analyze the settlement, stress, and plastic zone changes of surrounding rocks under four different schemes for a deep mining project of an iron mine in Shandong. The optimization ratio of vertical isolation columns per unit volume was proposed, and the scheme was optimized on this basis. The results indicate that the volume and position of vertical isolation columns in the deep mining process of gently inclined thick ore bodies have a decisive impact on their optimization effect. The optimal scheme is to leave a vertical isolation column with a width of 20 m and a thickness of 41 m on the 8^# vertical survey line where the settlement peak is generated (Scheme 4), which generates the maximum unit volume optimization ratio of settlement peak, stress peak, and plastic zone. Compared to Scheme 2, Scheme 4 can ensure the stability of the surrounding rocks more effectively. Compared to Scheme 3, Scheme 4 can extract an additional 461 700 tons of iron ore and 272 403 tons of refined iron ore powder, increasing the net profit of the enterprise by about 54.48 million yuan and increasing the net profit income by about 11.20%. The research results can provide some reference for the optimization and application of vertical isolation column retention schemes in similar mines.

Tieshanlong Tungsten Industry Huangsha mining area have the problems of low mechanization level, large quantity of mining preparation and cutting engineering, high labor intensity and large dilution loss rate for original mining technology. In order to solve these problems and improve the mechanization degree and ore utilization rate, according to the development experience of medium-diameter long holes in similar mines, combined with the grooving process of medium-long holes, the coordinated and efficient caving of upward medium-long hole and downward medium-diameter long hole was realized. The medium diameter long hole stage subsequent caving method was developed to mine steeply inclined thin ore body, and representative test blocks were selected for industrial tests. The industrial test results show that compared with the sublevel drilling stage caving method, the medium-diameter long hole stage subsequent caving method reduces the explosive unit consumption by 36.5%, and reduces the loss rate and dilution rate by 60% and 16.8%, respectively. The year-on-year ore volume and WO₃ metal extraction volume increase by 16.7% and 19.0% respectively, and the net profit increases by 729 500 yuan. The results can confirm the significant economic and social benefits of the mining technology of steeply inclined thin ore body, and provide a feasible scheme for long hole blasting mining of steeply inclined thin ore body.

Aiming at the problems faced by the selection of mining methods in the process of open-pit to underground mining in Sijiaying Iron Mine, based on the complex deposit occurrence characteristics of the mining area and the mining technical conditions of the mining surface environment, the stage open-stope subsequent filling mining method and the sublevel open-stope subsequent filling mining method were proposed, and the traditional staggered arrangement of ore transportation was optimized. The results show that the mining method of combined mining of scraper and pit truck in stage can effectively shorten the transportation distance of scraper and improve the transportation efficiency. When the stage height of the optimized mining method is 60 m, the height of the chute in the mining area is reduced by 30 m, and the number of chutes in the panel area is reduced from 6 to 2, which reduces the amount of preparation work and reduces the mining cost. The key problems that should be paid attention to in the selection and implementation of mining methods in this mining area are pointed out, in order to provide a guidance for the open-pit to underground mining work in Sijiaying Iron Mine.

The development and utilization of mineral resources not only provides a material basis for the development of the national economy, but also a key “battlefield” for carbon emission reduction under the “dual carbon” goals. In order to realize the low-carbon development of mines, based on the previous evaluation indexes of mining scheme optimization, the carbon performance related indexes were introduced, and the weighted grey relational mining scheme optimization model considering carbon performance was constructed. Taking a mine in China as an example, in addition to safety, economic and technical indicators, carbon performance indicators such as average carbon performance were introduced. The weight of each index was comprehensively determined using game theory, and the four mining schemes of stage room subsequent filling mining, open-pit stratified stepped mining, open-pit stratified stepped mining (35%) and stage room subsequent filling combined mining, open-pit stratified stepped mining (60%) and stage room subsequent filling combined mining were evaluated. Finally, it is determined that open-pit stratified stepped mining is the optimal scheme. Compared with the optimization results without considering carbon performance, the introduction of carbon performance index makes the weighted grey relational grade of each scheme change, which proves that it is of great significance to consider carbon performance index under the “dual carbon” goals, which meets the requirements of developing green mining and can provide reference for mining scheme optimization of mines under the “dual carbon” goals.

To address the issues of short setting time, poor water resistance and inadequate strength when β-hemihydrate phosphogypsum (β-HPG) is used as backfill cementing materials, two industrial solid wastes, carbide slag and silica fume were introduced. The effects of these wastes on the workability, water resistance, and strength of β-HPG were analyzed. The microstructure and pore structure of the modified β-HPG were investigated by SEM. Additionally, the environmental behavior, cost, and carbon emissions of the modified β-HPG were evaluated. The results indicate that the combined use of carbide slag and silica fume significantly extends the setting time of β-HPG slurry and enhances its fluidity. After modification, the compressive strength of β-HPG backfill is substantially increased, reaching a 28-day strength value of 36.6 MPa, with a reduced water absorption rate of 2.7% and an elevated softening coefficient of 0.885. The incorporation of silica fume and carbide slag can improve the micromorphology and pore structure of β-HPG backfill. The generated calcium silicate hydrate, a hydraulic hydration product, enhances the compactness of backfill. Carbide slag and silica fume effectively neutralize residual acids in the β-HPG and immobilize phosphorus and heavy metal elements within the hardened body. When the content of carbide slag is 10% and the content of silica fume is 15%−20%, the β-HPG cementing material exhibits favorable economic and environmental benefits.

Aiming at the problem of large solid waste reserves and high processing costs in Western Mining Group Co., Ltd., in order to achieve the reuse of solid waste and reduce the filling cost of mines, Xitieshan and Bolun Mining were selected as test objects. Through indoor and on-site industrial tests, researches were conducted on the proportion and application of filling cementitious materials based on industrial metallurgical solid waste replacing the cement. The results show that Xitieshan uses the new type of solid waste based cementitious material to fill the first and second step mining stope of the mine. The 28-day strength of filling under the two proportioning schemes is 2.5 MPa and 1.1 MPa, respectively. The annual consumption of solid waste is 14 625 t, saving the filling costs of 2.036 1 million yuan. Bolun Mining adopts the new formula to treat the filling layer, and 28-day strength of the filling body is 0.99 MPa. The annual consumption of solid waste is 5 623 t, increasing the filling cost by 43 240 yuan. Through the utilization of solid waste resources, Western Mining Group Co., Ltd. can process 20 248 t of solid waste throughout the year, saving the filling costs of 1.603 7 million yuan.

In order to study the mechanical properties and optimal ratio of carbon nanotube modified superfine cement-based grouting materials, carbon nanotubes, superfine cement, dispersant, defoamator and polyacrylate emulsion were used as raw materials based on three-factor and four-level orthogonal test. The water-cement ratio and the content of carbon nanotubes and polyacrylate emulsion were used as control factors. The viscosity, fluidity, setting time, uniaxial compressive strength and elastic modulus of the grouting slurry were tested. The influence of each factor on each index was determined through range analysis and variance analysis. The uniaxial compressive strength and elastic modulus were selected as the index for coupling, and the coupling value was analyzed by range, variance and multivariate linear regression analysis to obtain the optimal ratio and verify it. The results show that the uniaxial compressive strength and elastic modulus of the test block decrease with the increase of the water-cement ratio. With the increase of carbon nanotube content, the uniaxial compressive strength of the test block increases first and then decreases, and the elastic modulus shows a trend of increasing first, then decreasing and then increasing again. With the increase of polyacrylate emulsion content, the uniaxial compressive strength of the test block increases first and then decreases, and the elastic modulus shows a decreasing trend. After the uniaxial compressive strength and elastic modulus of the test block are normalized, the weight of 0.6:0.4 is added and coupled, and the optimal ratio of grouting materials is obtained by range and variance analysis. Through multivariate linear regression analysis and laboratory test verification, the optimal ratio is water-cement ratio of 0.6, carbon nanotubes content of 0.4%, polyacrylate emulsion content of 2.5%. The research results can provide a reference for the optimal ratio of carbon nanotube-modified superfine cement-based grouting materials.

In order to solve the problem of low comprehensive utilization rate of circulating fluidized bed fly ash (CFBFA), coal mine backfill materials were prepared by adding a small amount of cement with CFBFA as the main raw material. The differences in physical and chemical properties between CFBFA and fly ash were compared. On this basis, the control variable method was used to explore the effects of mass concentration, cement dosage and synergist dosage on the fluidity, bleeding rate and compressive strength of backfill materials. In addition, the optimal mix proportion was selected and engineering test was carried out based on a coal mine filling project in Shanxi. The experimental results show that the CFBFA requires a large amount of water and has a high activity. The mass concentration and cement dosage are the key factors affecting the performance of the backfill materials. The higher the mass concentration, the worse the flowability of the filling slurry, the lower the bleeding rate, and the higher the strength of the filling body. The higher the cement dosage, the better the flowability and bleeding rate of the filling slurry, and the higher the strength of the filling body. Without the addition of synergist, the mass concentration is below 0.555, and the cement dosage is 200 kg/m³, the filling slurry meets the design requirements of flowability no more than 20 s and 28 day compressive strength no less than 3.0 MPa. However, the bleeding rate is greater than 2%, which does not meet the design requirements. The synergist can significantly improve the flowability of the filling slurry, reduce the bleeding rate, and reduce the cement dosage by up to 90 kg/m³. The suitable dosage of synergist is 5.0 kg/m³. Engineering tests have shown that the addition of synergists significantly improves the mixability and pumpability of the filling slurry. The flowability, bleeding rate, and compressive strength of the filling material prepared on site with a mass concentration of 0.595, cement dosage of 120 kg/m³, and synergist dosage of 5.0 kg/m³ can meet the engineering design requirements.

To address the challenges of selecting suitable tailings thickening devices for domestic mines due to the diversity of available options, a thickening device optimization method based on the AHP-TOPSIS evaluation model was proposed. Based on the actual filling situation of a certain polymetallic mine, 13 evaluation indicators were selected from aspects such as economy, site conditions, and technology. Three thickening device schemes, including vertical sand silo, deep cone thickener, and paste storage thickener, were comprehensively evaluated and optimized through expert scoring. By calculation and analysis, the comprehensive superiority of the three schemes is found to be 49.51%, 17.42% and 80.11%, respectively. Therefore, the paste storage thickener scheme is determined to be the best scheme. The result is consistent with the actual application situation on site in a certain polymetallic mine, which adopts a filling process based on paste storage thickener. The tailings processing capacity of a single paste storage thickener exceeds 100 t/h, and the tailings storage capacity exceeds 1 600 t. The highest bottom flow mass concentration of the thickener reaches 74%, with a good filling effect. This evaluation model can provide a new method for optimal selection of tailings thickening devices.

In order to clearly present the development process of slurry transportation and comprehensively analyze the key research points related to pipeline transportation in different stages, CiteSpace software was used to conduct co-occurrence analysis and cluster analysis on 494 articles included in the China National Knowledge Infrastructure (CNKI) literature database from 2006 to 2023. The study reveals the following findings. Firstly, the overall trend of changes in the number of publications presents an M-shape, which can be divided into a preliminary exploration period, an efficient growth period, and a stable development period according to the chronological order. Secondly, the research subjects present a distribution of stars around some experts, and there are limitations in the research perspective. Thirdly, the research contents focus on three aspects, including material preparation, transportation technology, and mining filling. The slurry ratio has expanded from focusing on the particle size distribution of tailings to the application of additives, enhancing the integration of various disciplines. Therefore, future efforts could involve strengthening the core position of relevant mining research institutions, attaching importance to cross institutional collaboration and communication, expanding the research group, refining the research scope of pipeline transportation, strengthening the research on filling materials, deepening the depressurization treatment of deep well transportation, and trying to integrate non Newtonian fluid research methods, so as to enrich the research on filling pipeline transportation in the domestic academic community.