Metal Mines In China Research Articles

Sulfonated corn stalk enhanced hydrogel adsorption for heavy metal from metal mine gallery effluent

There are various of abandoned metal mines in China, and a considerable amount of heavy metal contaminated water is generated through water–rock interactions and accumulated within metal mine gallery. Therefore, the effective removal of heavy metals from metal mine gallery effluent holds significant importance. In this study, sulfonated corn stalk (SCS) and acrylic acid was used to prepare the double network hydrogel SCS-gel. The maximum allowable compression force for the SCS-gel was about 3 times than that of raw hydrogel. The SCS-gel exhibited a stable adsorption capacity within the pH range from 2.0 to 6.0. The maximal adsorption capacities of Pb2+ and Cu2+ on the SCS-gel were 111.6 and 370.2 mg/g, respectively. The functional groups of –OH, C-O, C = O, COOH, and −SO3- were participated in the adsorption process through coordination and electrostatic interactions. The SCS-gel exhibited promising reusability as the adsorption efficiency for Pb2+ and Cu2+ remained at approximately 100 % within 10 cycles of adsorption–desorption. The SCS-gel had an excellent removal efficiency for Pb2+ (99.8 %), Cu2+ (99.1 %), Mn2+ (97.4 %), Zn2+ (98.8 %), and Al3+ (95.7 %) from actual metal mine gallery effluent by dosage of 5 g/L with the initial concentrations of Pb2+, Cu2+, Mn2+, Zn2+, and Al3+ were 4.352, 29.20, 13.02, 7.016, and 30.47 mg/L, respectively. In the fixed-bed experiments, the Thomas model has a good description for the breakthrough curves of these heavy metals. These results confirmed the possibility of adopting SCS ethers for hydrogel fabrication and verified its great potential for the practical application for the removal of heavy metals from metal mine gallery effluent.

Mechanism, prevention, and control of mining-induced dynamic disasters in underground metal mines in China: Challenges and solutions

Mechanism, prevention, and control of mining-induced dynamic disasters in underground metal mines in China: Challenges and solutions

A Study on the Performance of Self-Leveling Mortar Utilizing Tungsten Tailings as the Aggregate

A significant quantity of tailings is produced during the development of different metal mines in China. In particular, fine-grained tailings pose challenges to the sustainable development of the mining industry. This study examines the utilization of finely ground tungsten tailings as a replacement for natural aggregates in self-leveling mortar (SLM). The study examined the impact of the aggregate-cement ratio, cement mix ratio, and varying substitution levels of different grain sizes of tungsten tailings on the flow properties, mechanical properties, and dimensional change rate of SLM. Additionally, the role of tungsten tailings in SLM was analyzed using XRD, FTIR, and SEM methods. The findings demonstrated that the utilization of sulphoaluminate cement (SAC) had a notable impact on improving the initial strength of the SLM. Additionally, a high aggregate-cement ratio negatively affected the fluidity of the SLM. The doping of tungsten tailings improved the grading relationship of the SLM. Substituting tungsten tailings of 38–75 μm grain size for natural aggregates in the preparation of SLM did not have a negative impact on its performance. In fact, substituting 60% tungsten tailings had a positive effect on the 28-day mechanical properties of the SLM. The compressive and flexural strengths of the SLM after 28 days were 26.53 MPa and 9.06 MPa, respectively, which were enhanced by 18.81% and 26% compared to the control group (C0). According to the environmental leaching test, SLM can effectively fix the heavy metal ions in tungsten tailings, and the leaching concentration of heavy metals is significantly reduced after long-term curing. The doping of finely fragmented tungsten tailings accelerated the process of hydration, resulting in the creation of hydrocalcium zeolite crystals in the latter phases of hydration. Furthermore, an increase in tailings substitution resulted in the production of a greater amount of hydration products, specifically C-S-H gels.

Metal-mining-induced sediment pollution presents a potential ecological risk and threat to human health across China: A meta-analysis

Aquatic sediment polluted by potentially toxic elements (PTEs) from mining activities represents a potential health “time bomb” for humans and the local ecology, but the integrated analysis of pollution and hazards of PTEs in sediment around typical metal mines in China is limited. Presently, the associated pollution status, spatial distribution, and ecological and health hazards of Cd, Cu, Zn, Pb, Cr, and As were investigated through index evaluation, spatial analysis, health risk assessment models, and Monte Carlo simulation. Overall, the sediment exhibited varying degrees of PTE contamination; notably, the level of Cd was 104.85 times higher than its background value, and it became the most enriched element in the surveyed sediment, followed in descending order by Cu, As, Zn, Pb, and Cr. Nationally, over 64.5% of metal-mining-affected sediment presented a very high ecological risk, contributed mostly by Cd (43.2%–98.7%) followed by As, Pb, and Cu; the risk contributed by both Cr and Zn was found to be negligible. The adverse health risk posed to children by most sediment was 1.72 and 6.46 times higher than that posed to adults for cancerous and noncancerous risks, respectively. The potential noncarcinogenic risks were mainly caused by As, which contributed over 78.9% of the Hazard Index values, then followed by Pb (>9.3%). For both children and adults, the carcinogenic risk of PTEs decreased in the following order: As > Cd > Cr > Pb. The investigated sediment was found seriously affected by nearby metal mines, especially those in regions with long-term and large-scale nonferrous-metal-mining activities. This study could provide a reference for policymakers to develop control strategies for PTE pollution in sediment around mining areas.

What Influences Miners' Safety Risk Perception?

The risks faced by the mining industry have always been prominent for every walk of life in China. As the direct cause of accidents, individual unsafe behaviors are closely related to their risk perception. So, it is important to explore the factors affecting miners’ risk perception and analyze the influencing mechanisms between these factors and risk perception. The questionnaire survey method was used to collect the data of risk perception from nearly 400 respondents working in metal mines in China. Exploratory factor analysis and confirmatory factor analysis were used to analyze and process collected data. The impact of four factors affecting miners’ risk perception was verified, namely: organizational safety atmosphere, organizational trust, knowledge level, and risk communication. Then, regression analysis, Pearson correlation analysis, and structural equation model analysis were used to examine the effect of the four influencing factors on miners’ risk perception. The four influencing factors all have a positive impact on miners’ risk perception; knowledge level has the largest explained variation of miners’ risk perception, followed by risk communication. Organizational trust and organizational safety atmosphere have an indirect and positive impact on miners’ risk perception intermediated by knowledge level and risk communication. The results offer four important aspects of mine safety management to help miners establish quick and accurate risk perception, thereby reducing unsafe behaviors and avoiding accidents.

Key Engineering Technologies to Achieve Green, Intelligent, and Sustainable Development of Deep Metal Mines in China

Abstract The object of this article is to present the innovative technology system for the deep mining of metal mines in China. Based on the current situation and major problems of deep mining of metal mineral resources in China, the key engineering technology development strategies to solve the problems, such as the green intelligent mining modes, are proposed, which is conducive to ensuring the safety of mineral resources supply and the sustainable development of the national economy in China.

Developments and prospects of microseismic monitoring technology in underground metal mines in China

Developments and prospects of microseismic monitoring technology in underground metal mines in China

Characteristics and Risk Assessment of Soil Polluted by Lead around Various Metal Mines in China.

The contamination of soil by lead (Pb) is a serious and widespread problem in China, especially in mining areas. This paper summarized the available data regarding Pb-contaminated soils around various metal mines in China. Based on these data, the Pb concentration in the soil and its temporal and spatial changes were analyzed. Potential ecological hazards and adult lead models were also used to estimate ecological and health risks. The results indicated that the concentration of Pb was closely related with the type of mine. Compared with other types of mine, soil around lead-zinc (Pb-Zn) and tin (Sn) mines with high Pb contents in the metallic ores and high pollutant emission coefficient were more strongly polluted by Pb. The characteristic spatial and temporal variations of Pb pollution status in China were clarified, and the results showed that the concentration was high in the southern, southwestern, and central regions of China where many mining areas were located, and the mean value passed a turning point in 2012. Ecological risk assessments indicated that some areas around mines were at considerable to high risk, and the risk was relatively severe in Pb-Zn mining areas. According to the adult lead model, Pb-Zn mines had a greater impact on blood Pb concentration than the other types of mine.

Practical Experience in Large-Scale Development of Zijinshan Low-Grade Gold-Copper Mine

The Zijinshan gold-copper mine, in spite of the low-grade nature of the ore, has become one of the largest production-scale and most profitable non-ferrous metal mines in China. The successful application of hydrometallurgy as well as proper engineering design are the key factors for large-scale development of the Zijinshan gold-copper mine. In this contribution, the practical experience acquired in the development of the Zijinshan gold and copper mines is summarized. This covers most aspects of the production process including mining, beneficiation, ore stacking, heap (bio)leaching, carbon-in-leach, solvent extraction, electrowinning, wastewater and tailing treatments. The authors believe that this practical experience will not only help to promote the development of hydrometallurgy, but can also serve as a model for other gold and/or copper plants around the world.

Numerical simulation of stress wave interaction in short-delay blasting with a single free surface.

It is generally believed that stress wave superposition does occur and plays an important role in cutting blasting with a single free surface, in which explosive columns of several blast holes with short spacing are simultaneously initiated. However, considering the large scatter of pyrotechnic delay detonators that are used in most underground metal mines in China, the existence of stress wave superposition and the influence of this effect on rock fragmentation are questionable. In the present study, the stress wave interaction in short-delay blasting with a single free surface was studied through the use of the LS-DYNA code. Stress waves induced by two blast holes blasting with different delays were compared with the single blast hole case, and the effects of delay time, detonating location and spacing on stress wave superposition were investigated. The numerical results showed that for blast holes with a 1 m spacing, stress wave interaction only occurs when the delay time is 0 ms and does not occur for blasting with delays of more than 1 ms. An increase in the duration of a stress wave via optimizing the detonation location does not improve the stress wave interaction. For a 1 ms delay, stress wave superposition only occurs when the spacing is more than 4 m, which is a rare case in practice. The results indicated that the occurrence of stress wave superposition for blasting with a single free surface is strictly limited to conditions that would be difficult to achieve under the existing delay accuracy of detonators. Therefore, it is unrealistic to improve fragmentation via the stress wave interaction in field blasting. Furthermore, the numerical results of the stress wave interaction also show that there would be a great potential to reduce the hazardous vibrations induced by short-delay blasting by using electronic detonators with better control of delays in an order of several milliseconds.

Monitoring and statistical analysis of mine subsidence at three metal mines in China

Mine subsidence is a regional geological hazard in China. To evaluate whether a power law describes the frequency–size statistics of mine subsidence, as for earthquakes and floods, we studied the frequency–size statistics of mine subsidence at three metal mines in China (Jinchuan Nickel Mine, Sanshandao Gold Mine, and Jingerquan Nickel Mine). Data sets for these mines consisted of 1088, 345, and 101 Global Positioning System (GPS) monitoring points, covering monitoring periods of 14.5, 4, and 3.5 years, respectively. Although these mines had different geological and hydrological settings, mining methods, and stress fields, their noncumulative frequency–size distributions for subsidence and uplift events can be described using power laws. The subsidence power-law exponent for these three mines ranged from 1.20 to 1.67, 1.49 to 1.94, and 1.01 to 1.17, with mean values of 1.46, 1.76, and 1.09, respectively. The power-law scaling for each mine was valid over the range from 2 to 455 mm, 2 to 566 mm, and 2 to 277 mm, respectively; scaling was positively correlated with the power-law exponent. The frequency–size statistics for subsidence events having different time scales showed an identical power-law dependence. The power-law behavior of uplift events was similar to subsidence events. This power-law behavior, its underlying mechanisms, factors influencing the power-law exponent, and the threshold between normal and extreme subsidence events are discussed herein. We conclude that the power-law distribution of mine subsidence events reflects the scale invariance of the subsidence system. This has important practical applications for subsidence hazard assessment and subsidence event prediction.

Intelligent Mining Technology for an Underground Metal Mine Based on Unmanned Equipment

Abstract This article analyzes the current research status and development trend of intelligent technologies for underground metal mines in China, where such technologies are under development for use to develop mineral resources in a safe, efficient, and environmentally friendly manner. We analyze and summarize the research status of underground metal mining technology at home and abroad, including some specific examples of equipment, technology, and applications. We introduce the latest equipment and technologies with independent intellectual property rights for unmanned mining, including intelligent and unmanned control technologies for rock-drilling jumbos, down-the-hole (DTH) drills, underground scrapers, underground mining trucks, and underground charging vehicles. Three basic platforms are used for intelligent and unmanned mining: the positioning and navigation platform, information-acquisition and communication platform, and scheduling and control platform. Unmanned equipment was tested in the Fankou Lead-Zinc Mine in China, and industrial tests on the basic platforms of intelligent and unmanned mining were carried out in the mine. The experiment focused on the intelligent scraper, which can achieve autonomous intelligent driving by relying on a wireless communication system, location and navigation system, and data-acquisition system. These industrial experiments indicate that the technology is feasible. The results show that unmanned mining can promote mining technology in China to an intelligent level and can enhance the core competitive ability of China’s mining industry.

Control of waste rock-tailings paste backfill for active mining subsidence areas

Serious damages to the environment due to surface subsidence and solid wastes are major disasters that occur in metal mines in China. The large-scale application of surface stacking of tailing pastes can possibly control active mining subsidence area in mines. In this paper, an approach was proposed to prepare the solid wastes of mines as the paste, which would be transferred to the subsidence area for backfilling to achieve integrated control of solid wastes and subsidence areas. A backfilling plan that features “horizontal partition and vertical stratification” was developed for subsidence areas. The influencing factors and patterns for the working performance of the backfill, namely strength, fluidity, permeability, and disintegration features, were investigated to prevent secondary disasters, such as the sudden collapses of backfill, downhole debris flow, and ore dilution and loss after control. The process parameters of the surface backfill in Tong Keng mines were determined as follows. The mass concentration of backfilling paste was 81%–83%, the added amount of waste rock was 25%–30%, the amount of added cement was 2%–5%, the 28-day uniaxial compressive strength was 1.5–3.0 MPa, and the permeability coefficient was 10−4 to 10−3 cm/s.

中国の非鉄金属政策と我が国への影響について

In this paper, China's policy on non-ferrous metals is analyzed. China is one of the largest producers and consumers of non-ferrous metals. Especially, it is the largest producer of many kinds of rare metals including rare earths, tungsten and indium. Since Japan heavily depends on China for these metals which are indispensable for high-tech applications, any change in China's policy on metals is likely to affect Japan's manufacturing industries and economy as a whole.Official Chinese documents including Five-Year Plan seem to show that China has two types of metal policy. One is to ensure a stable supply of base metals as their supply-demand situation is getting tighter. To this end, China encourages foreign companies to take part in the development of base metal mines in China, and also encourages Chinese companies to acquire greater amount of metals from abroad. The other is to control production and export of some rare metals. It appears that China aims to make its domestic industry more value-added by limiting outflows of raw materials. Measures such as export quotas and export taxes seem to be taken by China toward this end. The policy above will have a strong impact on metal supply as well as metal prices. This is particularly true for several rare metals that China almost dominates the world market in. Given these circumstances, Japan has to work hard to ensure a stable supply of rare metals. The actions we need to take include diversification of metal sources, recycling, R&D activities for material substitution, and close dialogue with China. Also, further examination will be needed as to the consistency of China's export control with the WTO.

Drift-driving in metal mines in China : Tunnelling 82, proceedings of the 3rd international symposium, Brighton, 7–11 June 1982, P255–260. Publ London: IMM, 1982

Drift-driving in metal mines in China : Tunnelling 82, proceedings of the 3rd international symposium, Brighton, 7–11 June 1982, P255–260. Publ London: IMM, 1982