Study On Key Technologies For Complicated Shape Stone Manufacturing Control And Wastewater Treatment

Stone industry in China has been developing very rapidly. Since2000, China isranked the number one place in the world in terms of its stone mining andmanufacturing capacity, stone product consumption and export volume. But acuteproblems exist in the current stone mining and manufacturing industry, among whichthe two prominent ones are:①due to inefficient stone manufacturing techniques withits low level of automation, stone industry is characterized by its low processingaccuracy, labor intensity, low production efficiency, and low utilization rate ofresources.②wastewater, waste residue, dust and noise pollution from stone miningand manufacturing industry, particularly the discharge of untreated wastewater,produce a hazardous and irrepairable impact on the environment, resulting in waterpollution and soil degradation. To address these issues, the dissertation aims toconduct a systematic research in these areas, which is the first of its kind, and worksout optimized practical solutions to these problems.Cutting stones into artistically designed products adds to the value of stoneproducts. But because of the diversity of stone products with complicated shape, thetraditional hand operated grinding method is labor intensive and of low accuracy, thusunable to carry out mass production. Based on the stone cutting equipment of modelQSJ made in China, this dissertation introduces the multi-axis computer numericalcontrol devices. By improving its mechanical, electrical control, and softwarestructure, this dissertation works out an improved QSJ bridge type stone cutter. Basedon this, this dissertation proposes the use of the large-size round cutting disc and bycontrolling its rotating angle to make the grinding surfaces in elliptic traces, and it setsup the5-axis control mathematical modeling to grind the varied complicated shape ofstone products in different specifications. Then, by applying the improved QSJ bridgetype stone cutter and the5-axis control mathematical modeling is presented in thisdissertation, and it further designs the5-axis control algorithm to achieve automationand computer numerical control in cutting the complicated shape stones. By practicalprocessing test, the automatical grinding manufacturing and numerical controltechnique in the improved stone manufacturing machines for complicated shape stonehave been achieved.To solve the problem of granite quarrying and processing wastewatercharacterized by high turbidity and high suspended substance contention, bycomparing the differences in the effects of currently used PAC flocculant and those ofthe humic acid flocculant, this dissertation works out a new type of flocculant:FA-PAC by mixing fulvic acids and polyaluminum chloride, and then analyzes thephysicochemical properties, structural features and mechanism of the FA-PAC flocculant which is to be applied in wastewater treatment. By conducting orthogonalexperiments, the ranking factors for flocculation effectiveness and the optimizedflocculation technical conditions are found. Under optimized conditions, thesupernatant liquid SS in treated wastewater is65mg/L, which meets the first-ordercriteria of the National Integrated Wastewater Discharge Standard (SS≤70mg/L) andcan be directly reused. The cost of the commonly applied PAC-PAM flocculant isabout1.950RMB Yuan per cubic meter of water, in contrast, the cost of the new typeof FA-PAC flocculant is only about1.136RMB Yuan per cubic meter of water, saving42%of the costs. It clearly indicates that the new type of composite flocculantFA-PAC is cost-effective in the treatment of wastewater resulted from granitequarrying and processing, which is essential in saving water resources for betterenvironmental protection, reducing production costs and maintaining sustainableeconomic development.When these two technical problems are solved, it is important to work out waysto maintain sustainable development from the economical perspective by analyzingthe potential relations between relevant factors influencing stone industrydevelopment and setting up a data-based vector auto-regression model (VAR).Clarifying relations between relevant factors of stone product output, the number ofpatent application claims, stone products export quota and amount of investment infixed-assets contributes to enhance the core competitiveness in stone industry. Butcurrent facts indicate that technological innovation in stone industry has beeninadequate and fails to boost stone industry as it is still characterized by its laborintensity and low level of technology, which greatly hampers the future developmentof stone industry in China. Based on this, this dissertation sets up a semi-parameterspace econometric model to describe the relativity of technological innovation indifferent regions in China so as to tap the potentials of technological creation, andexplore the impact of environmental governance on the sustainable development ofstone industry. Case analysis based on Fujian Province helps to map out theaggregation effect of areas with high level of stone industry development, areas ofSanming, Quanzhou, Xiamen and Putian form major stone enterprise clusters inFujian. These stone industrial clusters boost the industrial development andtechnological innovation of their neighboring underdeveloped areas.Finally, it is pointed out in this dissertation that stone industry development is asystematic project which requires joint efforts from both the government and theenterprises. An awareness of the importance of technological innovation andenvironmental protection is essential, and preferential policies should be given inthese two aspects. Restoring the ecosystem in stone mining regions is the mostpressing issue that demands immediate attention, efforts are needed to maximize theoverall effectiveness of the “nature-society-economy” trio and set up a circulareconomic development mode in stone industry.