Three types of gold deposits，which are the disseminated ore，auriferous quartz vein，and ore hosted in ductile shear zone have been identified in southern Qinling. The dating of the Baguamiao gold deposit in Fengxian, Xiaogouli gold deposit in Chengxian and Shangjiagou gold deposit in Kangxian gave rise to plateau age s (131.91±0.89)Ma, (197.45±1.13)Ma and (161.59±0.56)Ma respectively, consistent with the isochron ages. It is indicated that the metallization occurred in late Indosinian and early Yanshannian. The Ar³⁹/Ar⁴⁰ dating affirms their metal logenicages ranging from (131.91±0.89)Ma to (197.45±1.13)Ma which couple with the epoch in which the continent-continent collision and intracontinent orogene took place. Consequently, it is suggested that the collision-orogene, magmatic intrusion and location of gold deposits constitute an organic successive process. In line with the tectonic event, the large-scale metallization symbolizes the different representation of the same continental dynamics in the evolution of regional tectonics. 

The capability of several types of flat PDC cutters to withstand combined loads were tested and evaluated by the impact and cutting of single PDC cutter on granite in a linear impact-cutting table. The primary failure modes of PDC cutters withstanding different combined loads w, ere investigated and analyzed. The suggestions of enhancing PDC cutters to be suitable for drilling very hard rock have been made.

The particles of polymetallic nodules in hydraulic hoisting flows that are used for mining in deep sea are rather coarse, therefore their flow velocity is smaller than that of the surrounding water. The characteristic s of solid-liquid flows such as their density, concentration, elastic modulus a n d resistance were discussed. The wave propagation speed and the continuity and momentum equations of water hammer in coarse-grained solid-liquid flows were theoretically derived, and a water hammer model for such flows was developed.

Chromium salt is an important industrial material, but vast waste slag containing chrome(Ⅵ) is brought out in the process of its production. The slag is seriously harmful to environments and human health. The technologies on detoxification and comprehensive utilization of chromium-containing slag were summarized abroad and at home. And various methods were also described for the detoxification mechanism, technology process, and practical application effects in detail. A new concept for detoxification of chromium-containing slag, furthermore, was put forward by using microorganism.

Gold dissolves electrochemically in alkaline solutions containing ligands to form complex ions with gold ion. Therefore, selective leaching of noble metals is expected without dissolution of base metals such as steels, aluminum alloys in scrap treatment. Gold electrodes were investigated using linear sweep voltammetry, EQCM method and potentiostatic electrolysis in alkaline solutions containing thiourea, Na₂SO₃ and Na₂S₂O₃. The solution composition, electrode potential affect gold dissolution rate and current efficiency. The gold dissolved from anode electrode forms complex ions, suspension particles as compound precipitates and deposits on cathode electrode as a metal. Anodic efficiency for gold dissolution is between 10% and 22%. This is caused by the oxidation decomposition of sulfite ions and thiourea. The stability of t he alkaline solution containing these elements was also estimated by capillary electrophoresis technique.

Vast amounts of tailings are produced daily in bitumen extraction from the Athabasca oil sands. The coarse sand from the tailings stream is used to build dykes around the containment basin. The run-off slurry arrives at the water 's edge in the tailings pond at a solids concentration of about 3%～8% by mass. Settling of the solids takes place “relatively fast”, over several days, creating a “free water zone” that contains little solids. When the fine mineral solid s concentration has reached about 15% by mass, the suspension develops non-Newtonian properties. After 2～3 years, the suspension concentration reaches a value of about 30% by mass at which the settling rate becomes extremely slow. Methods to handle the already created tailings ponds and new approaches to eliminate the creation of new ones will be discussed both from the industrial and fundamental prospective.

Through a practical example of treatment of the flue gas from the remelting process of aluminum alloy tailings, the design an d calculation method of exhaust hood, as well as the principles and the equipment s of dust removal, smoke abatement and harmful gas elimination were studied. Com bination of centrifugal and wet dust removal can purify the dust high efficiently. The carbon black and harmful gases in the flue gas can be removed by adding a small quantity of activator to the absorption solution. The application results are that the dedusting efficiency is 97.43%, Cl₂ control efficiency is 88.03%, the exhaustfume blackness is lower than Ringelman number I, and the purification device resistance is 126Pa.

The elution of lead from vermiculite was investigated by using a novel biodegrad able chelating reagent, L-asparagic-N,N-diacetic acid (ASDA) and water solubled epolymerized pecticacid and comparing with a conventional chelating reagent, EDT A, as well as acetic acid. The influences of the reagent concentration, equilibrium pH and the suspension contact time on Pb extraction were examined. It is concluded that the acetic acid is not effective for Pb removal in any case due to its weak complexing ability with Pb. Although Pb is easier to be released by EDTA with stoichiometric amount, it is by no means the preferable alternative for the purpose because of its low biodegradability. On the other hand, ASDA and depolymerized pecticacid have the potential application because they are not only effective for Pb elution but also environmentally friendly.

Environmental consequences from sanitary landfill as well as incineration with power generation were compared in terms of life cycle analysis (LCA) for Laohukeng Wastedisposal Plant that is under consideration in Shenzhen. A variety of differences will be resulted from the two technologies, from which the primary issue that affects the conclusion is if the compensatory phase in power generation can be properly considered in the boundary definition of LCA. Upon the compensatory phase is taken into account in the landfill system, the negative environmental consequences from the landfill will be more significant than those from the incineration with power generation, although the reversed results can be obtained as the compensatory phase is neglected. In addition, mitigation of environmental impacts through the pollutant treatment in the incineration process will be more effective than in the landfill process.

The dynamics of forest ecology was studied. The pH values, electrical conductivities and concentrations of metal and nonmetal elements in rainfall, stream, throughfall and stream flow were investigated based on the data collected from a small mixed forest watershed of Pinusdensifor a siebet Zucc, Pinus thunbergii Parh and Chamaecypari sobtusa siebet Zuccex Endlat Kiryu nature reserve and a small barren watershed at Jakujo nature reserve, Ootsu, Shiga, Japan. The results show that both the mixed forest ecosystems of pine and cypress and the soil draw from granite affect the pH values and metal elements of rainfall. And the contribution of the mixed forest is greater than that of the barren. Moreover, the amount of input of most elements is larger than that of output in the ecosystem, which shows the elemental accumulation in the r elated forest ecosystem.

Environmental conscious manufacturing has become an important issue in industry because of market pressure and environmental regulations. An environmental risk assessment model was developed based on the network analytic method and fuzzy set theory. The “interval analysis method” was applied to deal with the on-site monitoring data as basic information for assessment. In addition, the fuzzy set theory was employed to allow uncertain, interactive and dynamic information to be effectively incorporated into the environmental risk assessment. This model is a simple, practical and effective tool for evaluating the environmental risk of manufacturing industry and for analyzing the relative impacts of emission wastes, which are hazardous to both human and ecosystem health. Furthermore, the model is considered useful for design engineers and decision-maker to design and select processes when the costs, environmental impacts and performances of a product are taken into consideration.