| Oil drilling cuttings is a waste produced in the process of shale gas production, which is paid attention to due to the damage to the ecological environment, the health hazard and restricting the sustainable development. The fly ash is the largest industrial waste in China, which brings great pressure on the environment, and how to recycle fly ash has aroused widespread concern. This topic utilizes fly ash which has the characteristics of gelation to prepare curing agent with mechanochemistry to cure oil drilling cuttings, and study the influence of various factors on the stability properties of the solidified body, for the safe disposal of oil drilling cuttings at the same time, achieving the purpose of “waste control by waste”.Firstly, this paper analyses the physicochemical properties of the fly ash, desulfurized gypsum by mineralogical analysis, and then carries out the activation test of the fly ash by mechanochemistry. Through studying the influence of the activator ratio, the activator and fly ash ratio, the ball milling time and the ball milling frequency on the mechanical strength of the solidified body, the optimal operating parameters of the activation of fly ash were determined: the activator ratio is 2∶1, the ratio activator and fly ash is 3 ∶2, the milling time is 2h, and the ball milling frequency is 40 Hz. The activation mechanism of fly ash was analyzed by means of XRD and IR. The results show that the glass bead structure of fly ash is destroyed and the pozzolanic activity is further stimulated under the action of the mechanochemistry. Because the polymerization degree of the Si-O-Si and A1-O-Si is decreased in the alkaline environment, C—S—H gel and ettringite are easy to generate in the activation system.Secondly, on the basis of previous experiments, usi ng fly ash as raw material, adding mechanical action, this paper carries out the cure experim ents of the fly ash by mechanochemistry for solidifying oil drill ing cuttings, compared with the effect of curing of cement. Through studying the influence of the dosage of curing agent, the ball milling time on the solidification effect of the oil drilling cuttings, the experimental results show that: The dosage of curing agent is proportional to the compressive strength of the solidified body, and is inversely proportional to the oil content and COD value of the l eaching solution. The lowest of the harmful substances in the leaching solution of the solidified body is the ball milling time of 5h. The stability of fly ash is better than that of cement solidified body. The concentration of harmful substances in the leaching liquid is lower than the national standard, and the performance is excellent. The maximum cure rate of fly ash is 55% and cement is 50%. The topic analyzes the solidified crystal structure and organic changes of the solidified body before and after By XRD and IR analysis method. The experimental results show that the fly ash curing to oil drilling cuttings is mainly physical sealing effect. The role of mechanical forces can degrade some of the oil in oil drilling cuttings.Finally, the results of the experiment are combined with the engineer ing practice. The treatment technology of oil drilling cuttings with activated fly ash by mechanical chemical method is designed. The method provides technical basis for practical engineering application. From the economic, social and environmental effects on the mechanical chemical method of activated fly ash solidified oil drilling cuttings for benefit analysis, analysis shows that the curing process can achieve the purpose of “waste control by waste” and saving resources. |
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