The Shiwuliqiao gold deposit，a small rock gold deposit in recent years，was found in the southern margin of the Heilongjiang Basin.The ore-bearing rocks of the deposit are the main silicified breccias and the wall rocks are andesites or alternation andesites.Through measurement regarding the regional petrophysical characteristics，the results show that the apparent resistivity of silicified breccias （ore） is quite different from wall rocks（andesite），but its closer to the dikes（diorite）.Secondly，the apparent polarization of silicified breccias is slightly greater than that of the wall rocks，and less than that of the propylitization andesite with surface oxidation.Thus the proposal of the geophysical work in the area will mainly focus on electrical parameters and aim at the targets with the characteristics of high resistances and polarizations.By analyzing the area of high magnetic ΔT，resistivity，polarizability characteristics and abnormalities combined with geological conditions in the region，it’s speculated that there were more than one NNE trending concealed fault belt existing in the deposit with high magnetic as a main indicator and a low resistance，low polarization as characteristics.In the both east and west sides of NNE high magnetic abnormal belts，the development of the secondary NE-NEE trends fault structure provided the main structure with ore containing in this region.The intersection area between the NE and NNE faults exist better gold mineralization.It will provide the basis for next step prospecting.
Baying quartz vein type gold deposit is located in the Fengshan area of Fengning，Hebei Province，which is the eastern part of Zhangjiakou-Fengning-Chengde gold metallogenic belt.The quartz vein type gold deposit occurs in the gold-bearing quartz veins of NWW fractured shatter zones.The ore bearing strata is Dantanzi group，Archean.The deposit consists of 13 known gold orebodies，in which I， III，VI orebodies are scale while others are small and lean.The shape and occurrence of orebodies are strictly controlled by fractured shatter zones and gold-bearing quartz veins.The orebodies occur as veins，long lens and podiform，which strike NWW.The wall rock of deposit is intensively altered，showed low to moderate temperature hydrothermal alteration，which is mainly manifested as silicification，sericitization，pyritization，chloritization and carbonatization.Gold mineralization is mainly developed in the quartz-polymetal sulphide stage.The gold deposit has obvious geological，geophysical prospecting criteria，including fracture structure，gold-bearing quartz vein，the mineralization and alteration，linear magnetic anomaly and linear polarization anomalous，etc.Through analyzing the geological characteristics，and geology，geophysical prospecting criteria of the quartz vein type gold deposit，this paper points out that it has the prospecting potential for medium quartz vein type gold deposit in this area.
Faults development at the Longmendian silver mine was mainly characterized by the NE，NW and NNE trending fractures，in addition，the NE and NNE trending fractures were closely related to mineralization.Namely，the formation and distribution of the ore bodies were controlled by fracture strictly.For the purpose of studying fracture fractal characteristics and the ore body，the box-counting dimension method was applied to calculate the fracture fractal dimension value （1.295）at the silver mine，and the value in the central area was approximately 1.319 with shear fracture.Fractal dimension values of the NE-NNE trending fracture with shear fracture related to mineralization at the whole and central regions were 1.197 and 1.237，respectively.The determination coefficient R2 was greater than 0.98，suggesting that the fractures at mining area had a good self-similarity.The NE-NNE trending fracture fractal dimension value（D>1.17）related to mineralization，and the trapped Taihua group gneiss was favorable metallogenic area.The fracture fractal dimension values D>1.25 at the whole reinog was as auxiliary index.The self-similarity was determined by fractal dimension value of quantitatively in this study，which functioned as guiding for the metallogenic prediction.
Rare earth elements（REE） have a wide range of applications from daily life to high-tech fields，so it is regarded as a strategic resource in many countries.In recent years，the United States and other countries generated dissatisfaction on China’s rare-earth policy because of their high dependence on chinese rare earth，and then China was sued to World Trade Organization（WTO）.In this paper，characters and reserves of global rare earths are introduced at first，then rare earths industry status of America are studied：its production has been ceased for a long time though reserve is abundant，rare earth elements supply is dependent on import and import is highly concentrated on one country，meanwhile，domestic supply chain is also incomplete，but its scientific research is leading the world. Its future possible policy options include：research and develop new technologies，authorize and fund USGS to assess REE resources，support and encourage exploration for REE，establish stockpile.Thus，the US rare earths self-sufficiency will get enhanced quickly，the World’s rare earth reserves and undiscovered resources will be sufficient to meet a variety of needs in the future.
Tongshi is located in the west of Yishu fault western Shandong uplift area，also it is a newly discovered gold-bearing concentrated area last century.Yanshan period’ Tongshi igneous complex intrusive and control the distribution of gold deposits.According to the previous experience of deposit exploration，and combining with the similar conditions adjacent areas’ prospecting experience inferred that Tongshi the forming limit depth of gold is under the bottom of Cambrian Changqing Group Zhushadong Group Dingjiazhuang dolomite paragraph.That is between Cambrian sedimentary cover with Precambrian crystalline basement unconformity.Above the unconformity surface is a favorable location for gold mineralization.According to the thickness of true formation and combining with stratigraphic occurrence.Calculating out of the ground to a vertical distance of unconformity is corresponding metallogenic gold prospecting target ore bodies buried depth.Estimating the depth of mineralization to provide a basis for deep drilling engineering design.
Although the high degree of geological conditions at the Zhengxiangbai Banner-Zhenglan Banner region，geological work was at low level with great prospecting potential.It presented the lower Permian Sanmianjing Group upper rock section and the upper Jurassic Zhangjiakou Group three rock section，and the silver content was higher.Due to the violent volcanic eruption，the structure of the hydrothermal activities related to volcanism during later volcanic period，volcanic rock and contains showed a large amount of volatiles，which played an important role in activation，migration and enrichment of silver and other metals.On this basis，according to the research area of silver and silver point of geological characteristics distribution laws and the metallogenic geological conditions，the region was divided into two silver metallogenic prospect areas.Therefore，strengthen the study of the metallogenic conditions of volcanic rock was meaningful to promote silver ore prospecting in volcanic rocks.
Dulan-Maduo area is located at transition area of Qinqikun Early Paleozoic made mountains and the Tibetan tethys north mountains late Paleozoic-Mesozoic era，and the study region had various different types of tectonic activity with frequent magmatic activity and superior metallogenic geological condition.On the basis of comprehensive investigation of geologic background in the study region，we analyzed the ore-forming geological conditions of muti-metallic deposit from the aspect of geochemical exploration in the Dulan-Maduo area.The results showed that the metallogenic belt for gold，copper，lead and zinc，chromium，molybdenum and antimony mineral prospecting potential was tremendous.In addition，comprehensive consideration of regional ore deposit genetic types of geochemistry，geophysics and mineral distribution characteristics，it was divided six metallogenic belt（Chaibeiyuan Au-Pb-Zn-Co metallogenic belt，Kunbei Fe polymetallic metallogenic belt，Kunzhong Au metallogenic belt，Kunnan Cu-Co-Au metallogenic belt，Buqingshan-Animaqing Cu-Au metallogenic belt，and Elashan Pb-Zn-Au-Ag metallogenic belt）and four metallogenic prospective areas（Kekesai Pb-Zn minerogenic prospect，Zhangmangang Au metallogenic prospect，Hatu Cu-Co-Au metallogenic prospective and Maerzheng metallogenic prospect），which will provide the next step prospecting direction for the study area.
For the purpose of studying the influence of cement-to-tailings mass ratio，mass fraction of solid phases and temperature for performance indicators of backfill material，control parameters of backfill materials which fitted mining requirements in different temperature ranges were determined.Considering engineering practice for magnetite in northern part，whole-tailings of the mine were selected as filling aggregate.A new cementing material supplied by a university was selected as binder.Based on the method of orthogonal test，the optimization experiment of backfill materials was performed.Sensitivities of the four indicators to the three factors were obtained.The four indicators were compressive strength，bleeding rate，collapsing slump and initial setting time.Changing trends of indicators with factors were likewise identified.Additionally，the most optimal composition was observed in this study.The results demonstrated that compressive strength can be improved and shorten the initial setting time by increasing cement-to-tailings mass ratio.The bleeding rate and collapsing slump were most sensitive to mass fraction of solid phases.Moreover，the properties of backfill material appeared to be better with goaf temperature increasing.When the temperature were around 10 ℃and 20 ℃，optimal proportion was that cement-to-tailings mass ratio was 1∶6 and mass fraction of solid phases was around 70%.When the temperature was approximately 30 ℃，optimal proportion of backfill materials presented with cement-to-tailings mass ratio about 1∶8 and mass fraction of solid phases around 72%.It can be concluded that applying different parameters under different goaf temperature was conductive to reducing the filling cost.
The effective selection of mining method has practical economic benefit for the mine.Through analyzing the selection factors of mining scheme with the AHP and VIKOR methods，the optimization model of mining scheme was established in this study.The model was applied to the selection of mining at a certain ore，after comparing and sorting the schemes mainly by calculating the numerical group benefit value，individual regret value and benefit ratio，the results showed that the selection results of calculation was the same with actual choice.Therefore，we can draw a conclusion that the method was practical and operable verified.Compared with the calculation process as well as the results of the two methods，the relationship between the positive ideal solution and the negative ideal solution was involved by the VIKOR method，and the method with more accurate results avoided the erroneous judgement that could be caused by the TOPSIS method.
To conduct scientific and rational evaluation upon mining methods for the exploiting of roof and bottom pillars in Sanshandao gold mine， factors influenced mining methods such as technology economy and safety were considered to establish a comprehensive evaluation index system.Analytic hierarchy process and entropy weight method were used in weight determing of evaluation index， then mining methods can be evaluated through empowerment combination and ideal point method.And the best scheme was obtained after calculating the approach degree of every mining method.Take Xinli mine field of Sanshandao gold mine for example，three schemes were designed for comprehensive evaluation，the relative closeness of the three schemes were 0.37，0.12 and 0.50，respectively.Hence，the third scheme was determined as the best scheme for the exploiting of roof and bottom pillars in Sanshandao gold mine.The result shows that the exploiting scheme choice based on empowerment combination and ideal point method is reasonable and reliable，and has important engineering significance to guide the exploiting of roof and bottom pillars.
In order to conduct a comprehensive safety evaluation of underground metal mine，a variety of risk factors affecting mine safety as well as their interrelations are analyzed and a hierarchical structure model including seven evaluation units and thirty-two risk indexes are built.Elements located at the same level are compared with each other to construct a judgment matrix by the means of analytic hierarchy process （AHP），and the weight coefficient of each risk factor can be further obtained through calculation.Expert scoring method is adopted to determine the membership degree matrix of qualitative indexes and fuzzy evaluation is then applied to determine the grade of mine safety condition with the premise that the safety condition has been divided into five grades.Apply this safety evaluation method to an underground gold mine of Shandong Province.The result shows that the mine is relatively safe while the weight ratios of safety management，unsafe behaviors of employee，safety education and training are 40.4%，25.3% and 12.5% respectively.The three factors have a significant role in mine safety and should attract more attention.Some effective measures should be taken to improve the safety level of the mine，because of the evaluation results of the hydrogeology，dust and noise conditions is“general safety”.Practice proves that the result obtained from this evaluation system is consistent with mine safety reality and the main risk factors affecting mine safety can be highlighted，which has a guiding significance for mine safety evaluation and developing a best management solution.
Stability of goaf was influenced by the static and dynamic factors，and has complex failure mechanism. In order to identify the goaf hazard level effectively，an identification method（RS-CPM method） based on the catastrophe progression method and rough set for the stability classification of metal mine goaf was presented.Six factors which were tensile strength，poisson ratio，volume of underground goaf，goaf aspect ratio，burial depth and goaf group influencing index，influencing the stability of metal mine goaf were selected in this paper according to the catastrophe progression method.These six factors were divided into three levels which were denoted respectively by B1，B2，B3.Analysis index system was built by these three levels.Then the relative importance of each level index were determined according to the rough set，so these levels were ranked.These indexes were concentrated as the catastrophe theory was used.The application of analysis for mine goaf was achieved finally.26 sets of domestic typical metal mine goaf instability data were collected to train and test on the analysis model，and the calculation result shows that the output of the model agrees with the actual situation.A new thoughts for instability of metal mine goaf was provided.
It is known that the sliding system is considered as the key links of mine production projects，now with the rapid improvement of mining mechanization level as well as the mining production，various forms of ore chute is becoming more and more extensively applied.However，in the chute drawing process，due to collision between ore crushing could produce a large amount of the dust，and the dust blowed to the ventilation system then diffused mainly by chute and the piecewise lane junction.Therefore，the dust around the working areas seriously polluted the environment and directly can harm the workers lives，and bring serious security hidden danger to production. Thus，in order to take effective measures for dust control to reduce slip ore dust during the process of escape，according to the present condition of Sanshandao gold mine combined with sliding system design of middle -600 m at entering wind shaft，and on the basis of reference of the dust control measures home and abroad，we discussed the mining system for the mine dust prevention measures，field environment has been improved after taking specific measures，also the desired results were achieved.
In order to meet the needs of gold mine production and comprehensive research，and according to the serious situation of chemical contamination，the HCl-HNO3-NH4HF2-KClO3 sealed vessel and Na2O2-KOH decomposition of high temperature melting system were established in this study.The Au，Ag，Cu，Pb，Zn，As，Sb，SiO2，Fe2O3，Al2O3，CaO，MgO and other 18 kinds of main，trace elements were determinated by atomic absorption spectrometry（FAAS and GF-AAS）and inductively coupled plasma spectrometry（ICP-OES）combined in geological samples.Green chemistry method is simple and it overcomes the problems such as low efficiency of the traditional exposure reagent aqua regia and mixed acid decomposition system utilization，serious environmental pollution，difficult to control the reaction process；Na2O2 combined with KOH can promote the process of ore melting，also will have a certain degree of offset matrix interference，precision（RSD） of the high grade Ag was up to 1.09% in thiourea medium，and chemical yield of the general metallogenic element was around 96%~107%.
Gold cyanide leaching for a arsenic and sulfur-bearing gold concentrate at Tianmashan，Tongling，was difficult due to the fine disseminated grain sizes and large amounts of the gold mineral wrapped by sulfides.In order to improve the efficiency of cyanide leaching，some of tests regarding acidic oxidation pretreatment in the systems of HCl-H2O2-addictive were carried out under the conditions that the proportion of grinding fineness at -0.048 mm was 90%，pulp density at 40 g/L，stirring speed at 400 r/min，reaction temperature at 60 ℃，reaction time at 4 h，dosage of HCl at 0.7 mol/L，dosage of H2O2 at 0.5 mol/L and dosage of ethylene glycol at 9 mL/L.As a result，the dissolution rates of iron，arsenic and copper were 48.1%，99.3% and 89.76%，respectively.What’s more，the leaching rate of cyanide leached gold increased 33.6% than that of cyanide leached directly after oxidation pretreatment to gold concentrate.It was evident that the crystal structure of sulfide was destructed after oxidation pretreatment，meanwhile，the As，Cu and other ingredients were dissolved.Thus，the gold cyanide leaching rate increased.Finally，some guidance for other similar arsenic and sulfur-bearing refractory gold concentrate processing is provided，which is expected to be meaningful for applicability and development of the oxidation pretreatment with the HCl-H2O2-ethylene glycol.
A gold refinery in Shandong used acidification HCN to treat wastewater containing cyanide.And then the plant used NaOH solution to adsorb produced during acidification，which not only took high cost and large amount of labor for workers，but also increasing Na+ in the system，then increasing the risk of clogging the pipeline by Na2SO4 in winter.To solve the problems above，this paper focuses on using lime solution to adsorb HCN，replacing NaOH solution.Tests in laboratory mainly explored the adsorption capacity of different concentrations lime to absorb hydrogen cyanide and the amount of barren liquor in the tests.Laboratory tests verify the feasibility of lime solution to adsorb HCN.
Because gold has the features of high corrosion resistance，good electrical conductivity and thermal conductivity，thus those features have been widely used in industry.Due to the existing gold smelting and processing technology had characteristics of long cycle，low efficiency，big reagent consumption，high energy consuming and operation process complex faults，therefore，in recent years，ultrasonic technology has already been applied extensively in various fields，developed well，and achieved good results.In this paper，we summarized and analyzed the application of ultrasonic technology in gold leaching，nanometer materials preparation，chemical plating and gold testing.The results demonstrated that compared with the application of traditional technology in the fields mentioned above，the ultrasonic technology presented the features of high efficiency，low energy consumption，wide application and ease of automation control，etc.With the development of the research on the basic theory of ultrasonic and continuous improvement of ultrasonic equipment，ultrasound technology will be favored and widely employed for the refractory gold ore，new material preparation as well as nondestructive testing，etc.
The structure，properties and preparation methods of hydrotalcite-like compounds were introduced firstly.Then，introduced the application of hydrotalcite compounds in the field of wastewater treatment，such as printing and dyeing wastewater，phosphates containing eutrophic wastewater，halogen containing wastewater and wastewater containing heavy metal ions and refractory organic wastewater.Of hydrotalcite compounds in the treatment of wastewater containing heavy metal ion research deeply，help to promote the improvement of resource disposal and recycling of metallurgical waste water and waste water treatment cost is reduced，has a broad application prospect.Finally，the application situation and prospects of hydrotalcite class materials is prospected.
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