In the industrial sector, hydrochloric acid is known as the “blood of industry”, with a global annual output of over 20 million tons, of which approximately 35% is used in the pickling process of the steel industry. In a 18% hydrochloric acid solution at 60 degrees Celsius, it only takes 5 to 10 minutes to effectively dissolve 2 to 3 millimeters of iron oxide scale on the surface of steel, which is 50% more efficient than mechanical rust removal. At the same time, the production cost is controlled at about 50 yuan per ton of steel. For instance, in the production line of Baosteel Group, the recycling rate of hydrochloric acid is as high as 99%. Through the spray regeneration system, 150,000 tons of waste discharge can be reduced annually, which complies with the environmental protection regulations introduced in China in 2020, strictly controlling the pH value of acidic wastewater within the range of 6 to 9.
In the field of chemical manufacturing, hydrochloric acid is the core catalyst for the production of polyvinyl chloride (PVC). To produce one ton of PVC, approximately 0.7 tons of industrial hydrochloric acid with a concentration of 31% are consumed. According to the data from the China Chlor-Alkali Industry Association in 2022, the domestic annual output of PVC reached 21 million tons. The resulting demand for hydrochloric acid increased the annual profits of related enterprises by 12%. Dow Chemical Company has raised the electrolysis efficiency of hydrochloric acid to 85% through an innovative process, saving 30% energy compared to traditional methods. This technological breakthrough directly led to a reduction of 800 yuan per ton in the production cost of PVC in 2021. It is worth noting that hydrochloric acid serves as an acidifier in the synthesis of drugs such as ibuprofen, with a concentration error of less than 0.5% to ensure that the product purity meets the pharmaceutical-grade standard of 99.9%.
In the water treatment industry, the consumption of hydrochloric acid for adjusting pH values accounts for 20% of the global total. A sewage treatment plant with a daily processing capacity of 500,000 tons needs to add approximately 5 tons of 30% hydrochloric acid every day to stably adjust the pH value of the influent from 9.5 to the legal range of 6.5-7.5, with a fluctuation range not exceeding 0.3. Based on the practice of the Gaobeidian Sewage Treatment Plant in Beijing, its intelligent dosing system has optimized the consumption of hydrochloric acid by 15% through real-time monitoring, saving over 3 million yuan in chemical costs annually. In the drinking water purification process, hydrochloric acid can effectively control the precipitation of calcium carbonate, reducing the rate of pipeline scaling from 3 millimeters per year to 0.5 millimeters and extending the service life of the water transmission system to 50 years.
The electronics industry relies on high-purity hydrochloric acid for chip etching. In nanoscale manufacturing, the content of metal impurities must be less than five parts per billion. In TSMC’s 5-nanometer process, the hydrochloric acid etching rate is precisely controlled at 0.8 nanometers per second, with a deviation of no more than ±0.1 nanometers. This level of precision ensures that the chip yield rate remains above 95%. According to SEMI statistics, the global semiconductor industry consumed over 800,000 tons of electronic-grade hydrochloric acid in 2023, and the market share of Chinese enterprises increased from 15% in 2018 to 25%. In food processing, the conversion rate of hydrochloric acid in the production of high fructose corn syrup can reach 98%, but the residue level must comply with the FDA standard of less than 10ppm.
In the field of oil and gas extraction, hydrochloric acid is involved in more than 15% of the production increase measures. When 28% acid solution is injected into the well at a flow rate of 2 cubic meters per minute, it can dissolve limestone layers and increase permeability by 300%. Halliburton’s 2022 report shows that the hydrochloric acid formula optimized with corrosion inhibitors can reduce the pipeline corrosion rate from 0.5 millimeters per year to 0.05 millimeters, lowering the operation cost of a single well by 200,000 US dollars. However, environmental risk control requirements are strict. For instance, the US EPA stipulates that the pH value of the reflux liquid must be neutralized to above 6.5, and the treatment cost accounts for 18% of the total project budget. It is precisely these precise application scenarios that enable muriatic acid to continue to play an irreplaceable role in the industrial value chain.
In the construction industry, hydrochloric acid is used for surface treatment of concrete. A 10% solution can remove 3 millimeters of cement slurry per hour, but the action time needs to be precisely controlled within 15 minutes to avoid corroding the steel bars. According to the construction records of the Shanghai Tower, the floor pickling process has increased the adhesion of the epoxy floor by 40% and shortened the construction period by 30%. The current circular economy model is promoting the development of hydrochloric acid recovery technology. For instance, the distillation purification device developed by GEM Company has increased the purity of regenerated hydrochloric acid to 99%, reducing the energy consumption per ton of processing to 150 kilowatt-hours, which is 50% lower than the production cost of primary acid. This perfectly aligns with China’s “dual carbon” goals.