The metallurgical production process not only has the harm of high heat energy and high potential energy determined by metallurgical technology but also has the danger of toxic, flammable and explosive, high temperature and high pressure of chemical production. At the same time, there are machines and tools, vehicles, and falling from height and other injuries, especially in the metallurgical production of molten steel, hot metal splash explosion, gas poisoning or combustion, explosion, and other accidents, the degree of harm is very serious. In addition, the main process and equipment of metallurgical production are highly dependent on the auxiliary system. For example, sudden power failure may cause molten iron and steel to solidify in the furnace, and a sudden drop in gas network pressure may cause serious accidents. Therefore, the hazard source of the metallurgical plants has the characteristics of complex risk factors, large mutual influence, a wide range of spread, and serious injury. Employees in the metallurgical industry should have a certain understanding of common accidents.
1. Splash accident
In the process of iron and steel smelting, molten steel and molten iron are high-temperature molten liquids, which do not cause splashing or explosion. The steelmaking process is mainly an oxidation process, and its reaction is mainly the reaction between steel slag. The reaction rate is closely related to temperature and gas pressure. At the same time, a large amount of carbon monoxide gas is produced. Whether the generated gas can be eliminated smoothly is directly related to the boiling of slag. The proper basicity and good fluidity of the slag make the molten pool boiling more active and reach the oxidation reaction conditions of carbon.
The carbon-oxygen reaction in the molten pool develops unevenly, and a large amount of CO gas is produced instantaneously, which may cause explosive splashing. When the oxidizing property of slag is too high and the temperature of the molten pool suddenly cools and then rises, explosive splashing may occur.
The hazards of splashing are as follows:
(1) the metal loss caused by splashing is between 0.5% and 5%. Avoiding splashing is equivalent to increasing steel production.
(2) splashing and smoking pollute the environment.
(3) it is difficult to remove the splashed ejecta. Serious splashing will cause accidents and endanger personal and equipment safety.
(4) due to the large amount of splashes, not only the removal of P and S is affected, but also the heat loss increases, and the water content of steel changes, which affects the stability of smelting control. Limit the increase of oxygen supply intensity.
2. Blast furnace collapse accident
In case of blast furnace collapse accident, molten iron, hot coke and high-temperature slag may lead to explosion and fire; pulverized coal injected into blast furnace may lead to coal explosion; blast furnace gas may cause fire and explosion; toxic gases such as blast furnace gas and hydrogen sulfide may lead to poisoning and other accidents. When dealing with the collapse accident of blast furnace, the staff should pay attention to:
(1) properly handle and prevent fire, explosion and poisoning accidents caused by hot molten iron, coal dust, blast furnace gas, hydrogen sulfide, etc;
(2) timely cut off all energy supply to a blast furnace, including pulverized coal, power supply, etc;
(3) monitoring the concentration of toxic gases in the air of the accident site and surrounding areas (especially the downwind area);
(4) if necessary, timely analyze the concentration of toxic gas at the scene of the accident and surrounding areas, and delimit the safe area.
3. Pulverized coal explosion accident
The pulverized coal explosion accident occurred in the closed production equipment may develop into system explosion, destroy the whole bituminous coal injection system and even endanger the blast furnace; the pulverized coal thrown outside the closed production equipment may lead to secondary dust explosion and secondary fire, and expand the accident damage. When handling the pulverized coal explosion accident, employees should pay attention to:
(1) timely cut off the power supply and other energy supply;
(2) it is strictly forbidden to open the equipment containing pulverized coal to put out the fire;
(3) it is forbidden to use a high-pressure water gun to spray pulverized coal;
(4) prevent secondary fire caused by burning pulverized coal.
Explosion accident of molten steel and hot metal
(1) it is forbidden to spray molten steel and hot metal with water to cool down;
(2) cut off any way of further contact between molten steel and molten iron;
(3) prevent the fire caused by the scattered molten steel and hot metal.
4. Fire and explosion
Key points for handling gas fire and explosion accidents. In case of gas fire and explosion accidents, attention should be paid to timely cut off all energy supplies leading to the accident site, including gas and power supply, so as to prevent further deterioration of the situation.
Gas, hydrogen sulfide, hydrogen cyanide poisoning accidents may occur in the smelting and coal chemical process. During emergency rescue, employees should pay attention to:
(1) quickly find the leakage point and cut off the gas source to prevent the continuous leakage of toxic gas;
(2) report to the local people's government promptly;
(3) set up a warning line to alert the surrounding residents.
In case of an oxygen fire accident, emergency rescue should pay attention to the following points:
(1) on the premise of ensuring the safety of rescue personnel, the leakage or oxygen supply channel shall be cut off quickly to prevent the continuous leakage of oxygen;
(2) special rescue measures shall be taken for burn personnel caused by oxygen fire.
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