Research On Design And Application Of Insensitive Crushing Agent

The traditional explosive blasting technology has been relatively mature,but there are harmful effects such as blasting vibration,blasting flying rock,dust pollution,noise and so on.It has led to the restricted use of industrial explosives in some specific environments.The safer non-explosives crushing technology also has many limitations such as high crushing costs,low crushing efficiency and poor crushing effect.Aim of this work is the study of a highly blunt,safe soil and rock crushing agent.It is capable of achieving rapid rock breaking while effectively reducing the harmful effects of vibration,flying rocks and dust generated by the blasting process.It provides a viable alternative to geotechnical blasting in special environments and is of great significance to the extraction of nationally important resources.This paper designs and prepares insensitive crushing agents,and investigates the performance of insensitive crushing agents through theoretical and experimental methods.Design and prepare the electric excitation device and conduct field rock crushing tests with insensitive crushing agents to investigate the ability and effectiveness of crushing agents to crush rock.The research conclusions are as follows:(1)The composition of the crushing agent was analyzed.Potassium nitrate was selected as the oxidizing agent and aluminum powder or coal powder was used as the combustible agent to design and prepare a variety of formulations of insensitive crushing agents.Through theoretical calculations,when the combustible agent is aluminum powder,aluminum powder content of 30～40%,the crushing agent has a higher explosion heat and explosion temperature;When the combustible agent is pulverized coal,the content of pulverized coal has little effect on the explosion heat and temperature of the crushing agent,and the 20%content of pulverized coal has the highest explosion volume.(2)In order to guide the parameters of charge density and charge length,the bulk density of the crushing agent was measured.When the content of combustible agent is 20～40%,the aluminum content has little effect on the bulk density of the crushing agent,which is about 1.00 g·cm-3.When the combustible agent is pulverized coal,the bulk density of crushing agent decreases with the increase of pulverized coal content.The bulk density of crushing agent is 0.75～0.91 g·cm-3.(3)In order to explore the safety of crushing agent in the process of production and use.The impact sensitivity,friction sensitivity and electrostatic spark sensitivity of various crushing agents were tested respectively,and the test results showed that there was no ignition phenomenon.The results showed that the crushing agents studied in this paper were highly insensitive and had high safety in production and use.(4)Through the ballistic throwing experiment,the work ability of the crushing agent was tested.When the content of combustible agent is about 30%,the crushing agent has the strongest work ability.The throwing power of crushing agent with 30%aluminum powder content is 16.04 J·g-1.The throwing power of 30%pulverized coal is 35.02 J·g-1.(5)In order to investigate the storage stability of crushing agents,this paper investigates the moisture absorption of crushing agent stored in different environments.In the open environment,the moisture content of the crushing agent containing aluminum powder is stable at 2.57%,which is obviously caked and can not be used.The moisture content of the pulverized coal is 0.45%.and the crushing agent can still be excited.In the sealed environment,the moisture content of aluminum containing crushing agent is stable at 1.26%,and the moisture content of pulverized coal is 0.20%.The crushing agent can be excited normally.(6)The igniting powder was prepared by using the mass ratio of copper oxide powder to aluminum powder as 3:2.the excitation device was designed and manufactured,and rock crushing test was carried out in the mine site.The rock crushing test results show that the excitation device can ignite and detonate the insensitive crushing agent safely and reliably,the insensitive crushing agent can achieve the effect of loose blasting,effectively reduce the production of blasting flying rock and blasting dust,and the blasting vibration speed is only 59%of the traditional industrial explosive blasting,which can effectively reduce the blasting vibration in rock blasting.Figure[32]table[27]reference[91]...