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Author: Yan Mingliang (Jiang'er Chemical Co., Ltd., Jiangsu Changhua Group, Changzhou 213004, Jiangsu). In the event of leaks of hydrochloric acid or sulfuric acid, serious disasters such as fires, explosions, corrosion, and poisoning can occur, posing a threat to public safety as well as the lives and property of people. It causes environmental pollution. **There has always been a strong emphasis on the management of hazardous chemicals. The Regulations on the Safety Management of Hazardous Chemicals, which came into effect on March 15, 2002 (hereinafter referred to as the \"Regulations\"), constitute the primary legal framework for the safety management of such chemicals. To minimize the occurrence of accidents as much as possible. The author explores the scope of damage and emergency measures in case of leakage incidents during the storage and transportation of hydrochloric acid and sulfuric acid, in order to draw the attention of relevant departments in various enterprises. l Physicochemical properties of hydrochloric acid and sulfuric acid 1.1 Physicochemical properties of hydrochloric acid Hydrochloric acid is miscible with water and soluble in alkaline solutions. It does not burn, but it is still very dangerous; it can react with certain reactive metal powders to release hydrogen gas. In the presence of cyanides, it can produce highly toxic hydrogen cyanide gas, and heat is released when it reacts with alkalis ； It has strong corrosivity, and its decomposition products are hydrogen chloride. Mountains can undergo a neutralization reaction with alkalis, releasing a large amount of heat; therefore, their contraindicated substances include alkalis, alkali metals, flammable or combustible materials, amines, etc. 1.2 Physical and chemical properties of sulfuric acid: Sulfuric acid has a strong affinity for water; it is miscible with water and can absorb moisture from the air and organic substances. When mixed with water or alcohols, it generates a large amount of heat ； Therefore, special care must be taken when diluting sulfuric acid; it should be poured into water slowly. Sulfuric acid can also act as an oxidizer; it reacts violently when in contact with flammable substances and organic materials, and can even cause combustion ； It releases a large amount of heat upon contact with water, which can cause boiling and splashing. The contraindications for sulfuric acid mainly include alkalis, alkali metals, water, strong reducing agents, flammable substances, and combustibles. Due to its inherent dangers and widespread use, it is important to prevent sulfuric acid accidents. 2 Accident Cases (1) On April 2, 2005, 100 meters east of Tianshan Street on National Highway 307 in Shijiazhuang, a tank truck carrying 5 tons of hydrochloric acid experienced a mechanical failure that caused the valve on the tank to break, resulting in the complete leakage of the hydrochloric acid loaded on the truck. This led to some damage to the road surface, but fortunately no injuries were reported. (2) On December 6, 2005, an accident occurred in the Pudong area of Shanghai involving a tank truck carrying concentrated sulfuric acid colliding with a truck; nearly 10 tons of concentrated sulfuric acid were released, contaminating almost 1,000 meters of waterways. No injuries were reported. (3) On December 24, 2005, a leakage accident occurred at a chemical warehouse in Zhejiang, with large amounts of hydrochloric acid spilling out from a ruptured storage tank, thereby contaminating the surrounding environment. (4) On January 10, 2006, a large truck carrying 20 tons of concentrated sulfuric acid was heading in the direction of Mianyang. When it reached kilometer 181 of the Mianyang-Guangyuan Expressway, it collided with the roadside barrier; the entire truck overturned beside the highway’s drainage ditch, and some of the concentrated sulfuric acid began to leak out. The driver suffered injuries to his legs. 3. Analysis of the leakage incident: 3.1 Calculation of the leakage volume. The actual storage amounts of hydrochloric acid and sulfuric acid at a certain chemical manufacturing company are shown in Table 1. Basic data: the diameter of the hydrochloric acid tank’s bottom is d = 4 m, its height is h = 10 m, and the radius of the crack is 0.1 m ； The bottom diameter of the sulfuric acid tank is d = 10 ore. With a height of h=8m and a crack radius of 0.1m, the actual amount of hazardous material present can be determined. The leakage rate of liquids can be calculated using Bernoulli’s equation in fluid dynamics; the leakage rate is denoted as Q. =In equation C A ID～(1), 90 represents the liquid leakage rate, in kg/s ； C. I is the liquid leakage coefficient (both values are set at 0.50) ； A is the area of the crack, in m; (it is assumed that A = r = 0.314 m) ； p is the density of the leaking liquid, in kg/m³; (for hydrochloric acid, IDI = 1,097; for sulfuric acid, P2 = 1,831.8) ； P is the pressure of the medium inside the container. Pa, (P=P0) ； P0 is the environmental pressure, in Pa, (P=Po) ； g is the acceleration due to gravity. g=9.8 m/s ； h is the liquid level height above the split 1:3 ratio, in meters; (for hydrochloric acid, h=10; for sulfuric acid, h=8). By substituting the values of various parameters into equation (1), we obtain: Hydrochloric acid: = 241.243 kg/s; Sulfuric acid: Q0 = 360.306 kg/s. The liquid leakage coefficient Cd relates to the leakage rate of liquids at normal pressure. It depends on the level of the liquid above the crack ； For the leakage rate of a liquid under non-positive pressure, it mainly depends on the difference between the pressure of the medium within window 1:3 and the ambient pressure, as well as the liquid level. When the liquid in the container is superheated, that is, its boiling point is lower than the temperature of the surrounding environment, the liquid suddenly evaporates as pressure decreases as it flows through the crack. The heat required for evaporation is drawn from the liquid itself, and the temperature of the remaining liquid in the container will drop to its boiling point at atmospheric pressure. Under these conditions, the percentage of liquid that evaporates directly during leakage can be calculated using the following formula: F = Co(7’ – ) / n (2), where C is the specific heat at constant pressure of the liquid, J/(·K), ； T is the temperature of the liquid before leakage. K. (all at normal temperature T=20°C) ； T is the boiling point of the liquid at atmospheric pressure, K. (Hydrochloric acid To=110. Sulfuric acid = 335.5) ； The latent heat of vaporization for liquids, J/kg; (hydrochloric acid = 167.15 ld/mol). Sulfuric acid = 9O9.27 ld/mo1). . Therefore, for hydrochloric acid, F=C(7’–To)/H = 0.0734; for sulfuric acid, F=C.(T–To)/ = 0.1017. The values calculated using equation (2) are almost always within the range of 0–1. In fact, the liquid that evaporates due to leakage will form clouds in the form of fine mist, which mix with the air and absorb heat as they evaporate. If the heat transferred from the air to the liquid mist is not sufficient to cause it to evaporate, some of the liquid mist will condense into droplets that fall to the ground, forming pools of liquid. Based on experience, when F>0.2, a liquid pool generally does not form ； When F