| As a large number of a by-product of the oil refining process in oil factories, spent bleachting clay was processed by de-oiling or open-air abandoned without de-oiling or sending to the garbage landfill for a long time. The environment was polluted and the resources were wasted. With the improvement of people’s life quality and the enhancement of environmental protection consciousness, a new process to reduce consumption of clay and a new idea of turning the waste into treasure were researched and developed. Not only it was beneficial to the protection of the environment and promote the rational use of resources, but can better implement the construction of environmental friendly society and resource-saving society for the purpose of policies and regulations.It is studied that the process of efficient recycled oil from waste clay in this paper, also researched that the two-step method catalytized the oil from spent bleachting clay preparation of biodiesel and studied deoiling waste clay was prepared for the mechanism environmental protection brick, the conclusion was summarized as follows:In the process of oil recovery from spent bleachting clay, through comparation of the organic solvent properties (boiling point/boiling range and toxicity),the properties of the oil from spent bleachting clay (color and oil extraction efficiency) and the nature of the deoiling waste clay (color), Screening the most suitable solvent of oil recovery from spent bleachting clay is 6# solvent; through orthogonal experiment and supplexperiment, and the aspect of the residual oil rate of spent bleachting clay and the cost ware considered, got ideal optimum process conditions of recycling oil from spent bleachting clay:solid-liquid ratio was 1:1.50, extraction temperature was 50℃, extracting time was 45 min, extraction times was 3 times.In the process of the two-step method catalytized the oil from spent bleaching clay preparation of biodiesel, by compared acid catalysts’ properties such as the water-soluble,the corrosion of equipment and the catalytic efficiency, chose ferric sulfate as catalyst for the esterification stage,and through the Box-Behnken design could determin esterification reaction conditions:acid catalyst was 5%, molar ration of methanol to oil was 14:1, the reaction temperature was 70℃, reaction time was 4h,Under this condition, esterification of esterification stage could reach 97.4%;center by Central Composite design could determine the best combination to transesterification was:molar ration of methanol to oil was 5:1,alkali catalyst was1.6%, reaction temperature was 68.5℃, the reaction time was 3h,Under this condition, the total yield of biodiesel was 86.7%.In order to ensure the ester exchange reaction completely, it was necessary to esterification. of esterification stage was the higher, the better, the condition could be determined by One Factor design:the dehydrant dosage was 1.6%, the esterification of esterification stage was 97.5%, then the recovery rate of acid catalyst was 23.5%.Used two-step method catalytized the oil from preparation of biodiesel that its quality indicators were conformed to the ASTM standard and very close to 0# Diesel fuell’.s quality standards.Considered the compressive strength, the safety and the cost, the deoiling waste clay could be used to produce the environmental protection brick and the compressive strength of mechanism for environmental protection brick was up to 16mpa from the standard of 15mpa.Used the mixture design optimization,the optimal proportion was that deoiling waste clay was 25.0%, cement wasll.8%, fine aggregate was 30.0%,small stones was 21.2% and lime was 12.0%.Used uniform design to optimize the production,the best process conditions was that molding moisture was 9%and the molding pressure was 20MPa;the mechanism for environmental protection brick was produced by deoiling waste clay and its compressive strength, flexural strength and freezing and thawing could be achieved to industry standards in the fly ash brick JC239-2001 MU15 requirements. |
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