Tanlu fault is a huge fault in eastern China.At present，there are still some key problems concerning the Tanlu fault.One is the length of Tanlu fault.The second is the horizontal slip distance and depth of the Tanlu fault.The third is the formation of Tanlu faults and its activity time.The fourth is whether it is the main controlling factor for the formation of the Jiaodong gold deposit.Based on a large number of geological，geophysical and geochemical results，combining the latest high-precision petroleum seismic exploration in Tanlu fault zone，the restoration of tectonic evolution shows that the rudimentary Tanlu fault occurred in the Mesozoic，mainly in the central orogenic belt of the southern section，and large-scale strike slips occurred in the Cenozoic （45～24 Ma）.The horizontal slip distance of the Tanlu fault is about 760 km.Tanlu fault is mainly a reconstructed fault，not the main control structure of the Jiaodong gold deposit.The primary ore-controlling structure of the Jiaodong gold deposit is a central orogenic belt.The formation and evolution of the Tanlu fault is closely related to the formation of many Mesozoic and Cenozoic pull-apart basins in eastern China.This study will provide a new idea for the study of tectonic dynamic environment and mineralization process in eastern China.
The gold fineness is a very important parameter for the gold deposit research and it is affected by many factors such as pH value and Na/(Na+K) of the ore-forming fluid.The water/rock interaction between ore-forming fluid and wall rock usually controls those important physico-chemical parameters.Jiaojia gold deposit is characterized by the intense water/rock interaction.No.Ⅰand No.Ⅲ orebodies in the Jiaojia gold deposit have different water/rock interaction due to different wall rocks.The study in this paper mainly focuses on the gold fineness comparison of the stage Ⅲ mineralization(quartz-polymetallic sulfide stage) between No.Ⅰand No.Ⅲ orebodies.The stage Ⅲ gold in two orebodies has been distinguished under the microscope.They were analyzed by the EPMA and the gold fineness was calculated according to analysis results.The mineral equilibrium phase image was calculated to estimate the variation tendency of pH value and Na/(Na+K) of the ore-forming fluid. Two points could been known according to this study:(1)The gold fineness in the stage III mineralization between No.Ⅰ and No.Ⅲ is similar;(2)pH value and Na/(Na+K) could be different when the ore-forming fluid was buffered by the pyrite-sericite-quartz alterated rock and K-feldsparation rock,but this difference has a little effect on the gold fineness.
The 460 gold deposit is located in the Mazhongshan area of Subei County,Jiuquan City,Gansu Province，and its geotectonic position is located in the Huangshan-Hongshishan-Lujing Late Paleozoic intracontinental rift zone of the Xingxingxia-Hanshan microplate,Kazakhstan Plate.The gold mineralization in the region is jointly controlled by tectonic,magmatic rocks,stratigraphy and metamorphism.460 gold deposit is a multi-phase medium-low temperature hydrothermal deposit,the origin of hydrothermal and ore-forming materials mainly come from atmospheric precipitation and ore-bearing wall rocks，mineralogenetic epoch is middle and late variscan,with a large number of gold veins and more than 110 large veins.10 representative gold veins were selected on the basis of previous data and indoor comprehensive research.The metallogenic regularity of gold deposits was summarized,and a prediction model of geochemical primary halo was established by field observation,isotopic geochemistry,inclusions test and primary halo rock geochemical survey.The predicted results show that there may be 21 blind orebodies in the depth of 10 gold veins，the drilling proved that the mine was good.
Based on the existing exploration engineering data and research results of Matigou gold mine，a 3D visual geoscience model of Matigou gold mine area was established by using Surpac software platform.The 3D visualization geoscience model visually and quantitatively shows the basic conditions of the terrain，stratum，structure and mineralization of Matigou gold mine.The comprehensively study about the spatial distribution of gold mineralization in the mining area was conducted.It is believed that Matigou gold orebody mainly extends along the northwest-south eastward direction.The toughness and brittle thrust nappe fault （F9） and its derivative and evolutionary structures in the Luohansi-Wayaoshang are the main ore-controlling structures in the mine area.The mineralization intensity decreases from high to low，showing discontinuous characteristics.Mineralization has a tendency to extend deep，and the middle section of 1 450～1 550 m is a favorable section for mineralization of the gold mine.Through the study of the distribution law of the mineralization of Matigou gold mine and the variation characteristics of mineralization intensity and the relationship between mineralization and structure，two prospecting targets were identified in the mining area.The research results provide foundation for the next prospecting work in the mining area.
Uncertainty always exists in the overseas mining investment environment.Based on related literatures，expert experience and the data from the World Bank，etc，risk factors of the overseas mining investment environment were identified.A risk evaluation index system was established with political policies，economy and finance，society and culture，and infrastructure facilities as four primary indexes.Delphi method was used to determine the index weights，and the secondary indexes were graded according to the data from the World Bank，etc and recognized grading rules.The principle of contingency theory was introduced to establish an evaluation model with incentive variable weights.Twelve countries were selected for applications.The evaluation results show that countries with lower mining environmental risks are Canada，the United States，New Zealand，and Romania，which are the preferred areas for mining investment；countries with general risks are Philippines，South Africa，Australia and Mexico，which are the sub-selected areas；countries with higher risks are Russia，Kazakhstan，Kenya and Brazil，which are the cautious-selected areas.Meanwhile，more attentions should be paid to the extreme indicators which may have adversely impacts on the operations of the project.Finally，some relevant suggestions were put forward，which may be helpful for the mining companies to reduce the investment risks and provide decision basis for the government to formulate overseas mining investment policies and implement classified management.
The roadway support has always been a difficult problem in the mining engineering，especially in the deep soft rock roadway，whether it can provide endurable and effective support directly affects the safety production and sustainable development of the mine.The composite supporting scheme of double layer bolt-mesh-anchor and U-shaped steel is frequently used in the deep roadway in Jinchuan mining area.In order to evaluate the supporting effect of this scheme，a tentative roadway was setted up on the 814 m ramp in No.2 mine.Through the combination of field monitoring and numerical simulation calculation，the supporting effect was evaluated，and an improvement measure was put forward.The results show that：（1）Under the present supporting conditions，the surrounding rock in the roof and both sides of the roadway are well controlled，but the floor heave is serious with the maximum displacement reaching 110 cm.（2）In view of the defects of the current supporting scheme，reinforcement measures，ranging from increasing the length of bolt，improving the strength of anchor rod to supporting the floor，were put forward.（3）An optimization scheme was designed，and the numerical simulation results show that the optimized supporting method can control the deformation of roadway surrounding rock effectively and solve the problems of the previous scheme.
In order to obtain the variation trend of frictional resistance in different concentration phospho-gypsum backfill slurry，the flow performance of the slurry was studied by shear rheological experiment and loop test.The results show that the frictional resistance of phosphogypsum backfill slurry increases multistep with the increase of concentration，and the higher the concentration，the faster the resistance increases.The research results show that under the condition of existing filling pipe network and filling ratio，displacement volume is less than 190 m3/h，frictional resistance change little with concentration of 50%~54%.Therefore，backfill slurry concentration can be raised to 54% for pipeline transportation，at this point the pipeline frictional resistance is around 0.2 kPa/m.In view of the complexity of mine backfill pipeline，the total resistance of transported backfill slurry will be increased，so the design of mine backfill system should make allowances for additional resistance due to the bend pipeline and slope.
Qinghai Province has a vast territory and rich mineral resources.Great breakthroughs have been made in gold mine geological prospecting over the last decade.The “gold belt” of Qinghai Province has been found in east Kunlun and other areas，which has promoted the development of the gold industry in Qinghai Province.In order to further implement the comprehensive，efficient，circular and economical utilization of mineral resources in Qinghai Province，collected and sorted out information of the gold industry mineral resources and the production status of major gold enterprises，also consulted a large number of literature materials，so that understand the distribution，characteristics，amount of gold resources，types of developed rock gold mines， flotation-metallurgical process，production index and research and development platform of rock gold mineral resources in Qinghai Province.This paper mainly introduce the latest research results of the refractory gold mines flotation，flotation tailings environmental gold extraction，biological pre-oxidation and medium temperature medium voltage pre-oxidation of gold concentrate in Qinghai Province.At the same time，the direction of the development of research and industry development was proposed，that is strengthen the study of technological mineralogy，the process investigation and diagnosis of concentration plant，the construction of green mines and so achieve comprehensive，efficient，circular and economical utilization of mineral resources，as well as coordinated development of mining development and ecological civilization .
In order to understand the distribution of ventilation resistance in mine ventilation system，provide better ventilation and resistance reduction，and to provide reliable basic information for ventilation design，network calculation and optimization，it is necessary to measure the resistance of mine ventilation system.The resistance of ventilation system was measured by base point method，and the parameters were determined for different measuring points.The measurement results were further calculated and analyzed from four aspects： evaluation of measurement accuracy，the distribution of ventilation resistance，the accumulation holes of mine and wind resistance.The results show that the layout of ventilation system and resistance distribution of Jiaojiazhai coal mine is reasonable，and the degree of ease of ventilation is easy.The wind resistance of the common air inlet wind roads in the three mining areas is large，and the facilities for regulating the air volume down hole in mines are too much，and the amount of air leakage from the damper is too high.It is recommended to replace the No.1 and No.2 fans and to strengthen the maintenance and management of the mine’s total return airway.
In order to promote cleaner production and promote the sustainable development of zinc smelting enterprises,the evaluation model based on game theory and fuzzy comprehensive evaluation was put forward on the basis of smelting process and mathematical method.Firstly,the weight values were calculated by the analytic hierarchy process and entropy weight method.Secondly， the final weight was determined by the game theory. Finally,the fuzzy comprehensive evaluation method was used to get the evaluation results.The results of the application examples showed that the cleaner production level of the enterprise is in the second level,which has great potential for cleaner production,among the six first level indicators in the index system,two indicators are in third levels,three indicators are in second grades, and one indicator is in the first level.And the evaluation model based on game theory and fuzzy comprehensive evaluation had a strong applicability in the cleaner production evaluation of zinc smelting enterprises and it would effectively promote the development of cleaner production.
In order to study the seepage characteristics and stability law of mudstone slope under the coupling of sudden drop of reservoir water level and different rainfall types，based on the unsaturated rock mass theory and Hoek-Brown criterion，the expression of slope stability coefficient under the coupling of reservoir water level and rainfall was derived by using limit equilibrium theory，and numerical simulation of mudstone slope was carried out by using Geo-slope software.The results show that the pore pressure decreases first and then remains unchanged when the reservoir water level drops suddenly.The farther the monitoring point is from the reservoir bank，the smaller the variation amplitude of pore pressure is.The slope stability coefficient decreases first and then increases with time，and then remains unchanged.The larger the reservoir water level dropping rate is，the smaller the minimum stability coefficient is and the earlier it occurs.The pore pressure increases first and then decreases under the condition of different static reservoir water level coupling different types of rainfall.The higher the static reservoir water level is，the larger the overall pore pressure is.When the reservoir water level drops suddenly and encounters occasional rainfall，the overall trend of pore pressure in slope decreases gradually and rises abruptly in the process of rainfall.The minimum stability coefficient is the smallest when the mean rainfall occurs at the 24~26 d of the sudden drop of the reservoir water level.The research results provide a reference for correctly understanding stability law of rock slope under the condition of sudden drop of reservoir water level coupled with rainfall.
Tailings is a huge source of environmental risk for mine，which seriously threaten the surrounding ecological environment and the lives of residents.The basic situation and environmental risk characteristics of tailings in Gansu Province were analyzed through site investigation and data collection，and the environmental risk prevention measures were proposed.Results showed that tailings in Gansu Province mainly distributes in Longnan area with a low level of safety，mainly in form of valley type，heavy tailings reservoir and small-sized reservoir. There are certain environmental risks，which threaten the surrounding water bodies，soil and atmospheric environment.The site selection，design and construction，monitoring facilities，ecological restoration and environmental emergency system are key tasks for preventing environmental risk of tailings in Gansu Province.
In order to improve the level of tailing ponds management，an improved evaluating method for safety harmony equation of tailing ponds is used.Firstly,construct an evaluation system,included nine evaluation factors.Secondly,combined with the entropy weight method and the dynamic excitation evaluation method,the weight information interval of evaluation index was calculated and the evaluation index value is adjusted cooperatively,and the relative closeness is ranked.Then,the harmony degree of the tailing pond is calculated by using the theory of harmony equation.Finally,the degree of harmony of the comprehensive evaluation results,the ranking of the indicators and the factors affecting the safety,and the results give reasonable suggestions and improvement measures.
The effect of a new pretreatment method i.e. mechanical activation on the solid-state and dissolution properties of arsenopyrite was studied.In a planetary ball mill，arsenopyrite was mechanically activated for 1 h at different grinding speeds.The analysis of particle size and specific surface area indicated that the particle size of arsenopyrite decreased rapidly at first and then increased slightly with increase of milling speed.The optimum particle distribution，minimum particle size value of 2.36 μm and maximum specific surface area of 2.667 m2/g can be observed at milling speed of 300 r/min.The morphology of arsenopyrite at different milling speeds was observed by scanning electron microscopy（SEM），and it was found that the surface of arsenopyrite formed micro-nano particles and amorphization degree significantly increased with the increase of milling speed.XRD（X-ray diffraction）analysis results showed that with the increase of milling speed，no phase transformation occured，but the amorphization degree of arsenopyrite increased to 72%， lattice distortion increased from 0.014% to 0.097%，and crystallite size decreased from 75.6 nm to 56.0 nm.The characteristic peaks of 217.2 cm-1and 273.7 cm-1of arsenopyrite were analyzed by Raman spectroscopy.It was found that the vibration of the characteristic peak located at 273.7 cm-1was more sensitive to the mechanical stress.Finally，the leaching tests of arsenopyrite were carried out by Fe2（SO4）3solution.The results showed that contrasted with unactivated arsenopyrite，total arsenic extraction from arsenopyrite has doubled to nearly 48.74% under the optimum milling speed of 300 r/min.
The acidic wastewater generated by gold smelting enterprise is generally treated by the lime neutrali-zation method and returned to the system，but the disadvantage of this method is that the chloride ions in the wastewater can not be removed.In order to eliminate the harm caused by the continuous deposition of chloride ions，an experimental study was carried out on smelting acidic wastewater.Usually，the principle of chloride ion removal is to replace chloride ions with other anions or remove chloride ions together with other cations.Cuprous oxide was used as precipitant and precipitated with chloride ion，so that to achieve the purpose of removal.In the experiment，in order to determine the best experimental conditions，the chloride ion is investigated under different pH，temperature and cuprous oxide dosage.The removal effect is measured by the chloride removal rate.Finally，the good experimental results of chlorine removal rate above 95% can be obtained under the condition that the pH value of the solution is 0.5，the amount of cuprous oxide is 10 mg/L，and the reaction rate is 20 min at room temperature.The results show that the use of cuprous oxide can effectively remove the chloride ions in the acid smelting acid waste water，and the formed cuprous chloride precipitate is stable in acidic wastewater and easy to be filtered and removed.In the actual production process，cuprous oxide also can circulating dechlorination，which saves production cost and provides a data reference to remove chloride ions from acidic for the same type of companies.
Environmental-friendly reagent Jinchan was used as a substitute for sodium cyanide to treat Xiajiadian gold mine,and the leaching effect of Jinchan and sodium cyanide was compared.The results showed that the leaching rate of Jinchan and sodium cyanide was 88.55% and 88.73% respectively,which was basically the same when the dosage of reagents was 200 g/t；When Jinchan dosage was 300 g/t，the leaching rate of 89.87% could be obtained，which was obviously better than the leaching effect of sodium cyanide under the optimal conditions；When using Jinchan，the adsorption and desorption effects were the same as that of sodium cyanide,with gold desorption rate of 98.99% and 98.97%, respectively；Jinchan as a substitute for sodium cyanide，could significantly improve technical and economic indicators，and moreover，in view of the non-toxicity of Jinchan，the invisible benefits of transportation，management，environmental protection and safety also would be obtained.
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