<unk>  production in 2000<unk>  is a very important commodity chemical, and indeed, a nation's<unk>  production is a good indicator of its industrial strength. World production in the year 2004 was about 180 million tonnes, with the following geographic distribution: Asia 35%, North America (including Mexico) 24%, Africa 11%, Western Europe 10%, Eastern Europe and Russia 10%, Australia and Oceania 7%, South America 7%. Most of this amount (≈60%) is consumed for fertilizers, particularly superphosphates, ammonium phosphate and ammonium sulfates. About 20% is used in chemical industry for production of detergents, synthetic resins, dyestuffs, pharmaceuticals, petroleum catalysts, insecticides and antifreeze, as well as in various processes such as oil well<unk> icizing, aluminium reduction, paper sizing, and water treatment. About 6% of uses are related to pigments and include paints, enamels, printing inks, coated fabrics and paper, while the rest is dispersed into a multitude of applications such as production of explosives, cellophane, acetate and viscose textiles, lubricants, non-ferrous metals, and batteries. Industrial production of chemicals The major use for<unk>  is in the "wet method" for the production of phosphoric<unk> , used for manufacture of phosphate fertilizers. In this method, phosphate rock is used, and more than 100 million tonnes are processed annually. This raw material is shown below as fluorapatite, though the exact composition may vary. This is treated with 93%<unk>  to produce calcium sulfate, hydrogen fluoride (HF) and phosphoric<unk> . The HF is removed as hydrofluoric<unk> . The overall process can be represented as: : Ammonium sulfate, an important nitrogen fertilizer, is most commonly produced as a byproduct from coking plants supplying the iron and steel making plants. Reacting the ammonia produced in the thermal decomposition of coal with waste<unk>  allows the ammonia to be crystallized out as a salt (often brown because of iron contamination) and sold into the agro-chemicals industry. Another important use for<unk>  is for the manufacture of aluminium sulfate, also known as paper maker's alum. This can react with small amounts of soap on paper pulp fibers to give gelatinous aluminium carboxylates, which help to coagulate the pulp fibers into a hard paper surface. It is also used for making aluminium hydroxide, which is used at water treatment plants to filter out impurities, as well as to improve the taste of the water. Aluminium sulfate is made by reacting bauxite with<unk> : :<unk>  is also important in the manufacture of dyestuffs solutions. Sulfur–iodine cycle The sulfur–iodine cycle is a series of thermo-chemical processes possibly usable to produce hydrogen from water. It consists of three chemical reactions whose net reactant is water and whose net products are hydrogen and oxygen. : (120 °C, Bunsen reaction) (830 °C) (320 °C) The compounds of sulfur and iodine are recovered and reused, hence the consideration of the process as a cycle. This process is endothermic and must occur at high temperatures, so energy in the form of heat has to be supplied. The sulfur–iodine cycle has been proposed as a way to supply hydrogen for a hydrogen-based economy. It is an alternative to electrolysis, and does not require hydrocarbons like current methods of steam reforming. But note that all of the available energy in the hydrogen so produced is supplied by the heat used to make it. The sulfur–iodine cycle is currently being researched as a feasible method of obtaining hydrogen, but the concentrated, corrosive<unk>  at high temperatures poses currently insurmountable safety hazards if the process were built on a large scale. Hybrid<unk> ycle The hybrid<unk> ycle (HyS) is a two-step water splitting process intended to be used for hydrogen production. Based on sulfur oxidation and reduction, it is classified as a hybrid thermochemical cycle because it uses an electrochemical (instead of a thermochemical) reaction for one of the two steps. The remaining thermochemical step is shared with the sulfur-iodine cycle. Industrial cleaning agent<unk>  is used in large quantities by the iron and steelmaking industry to remove oxidation, rust, and scaling from rolled sheet and billets prior to sale to the automobile and major appliances industry. Used<unk>  is often recycled using a spent<unk>  regeneration (SAR) plant. These plants combust spent<unk>  with natural gas, refinery gas, fuel oil or other fuel sources. This combustion process produces gaseous sulfur dioxide () and sulfur trioxide () which are then used to manufacture "new"<unk> . SAR plants are common additions to metal smelting plants, oil refineries, and other industries where<unk>  is consumed in bulk, as operating a SAR plant is much cheaper than the recurring costs of spent<unk>  disposal and new<unk>  purchases. Hydrogen peroxide () can be added to<unk>  to produce piranha solution, a powerful but very toxic cleaning solution with which substrate surfaces can be cleaned. Piranha solution is typically used in the microelectronics industry, and also in laboratory settings to clean glassware. Catalyst<unk>  is used for a variety of other purposes in the chemical industry. For example, it is the usual<unk>  catalyst for the conversion of cyclohexanone oxime to caprolactam, used for making nylon. It is used for making hydrochloric<unk>  from salt via the Mannheim process. Much is used in petroleum refining, for example as a catalyst for the reaction of isobutane with isobutylene to give isooctane, a compound that raises the octane rating of gasoline (petrol).<unk>  is also often used as a dehydrating or oxidizing agent in industrial reactions, such as the dehydration of various sugars to form solid carbon. Electrolyte<unk> ic drain cleaners usually contain<unk>  at a high concentration which turns a piece of pH paper red and chars it instantly, demonstrating both the strong<unk> ic nature and dehydrating property.<unk>  acts as the electrolyte in lead–acid batteries (lead-acid accumulator): At anode: : At cathode: : An<unk> ic drain cleaner can be used to dissolve grease, hair and even tissue paper inside water pipes. Overall: : Domestic uses<unk>  at high concentrations is frequently the major ingredient in<unk> ic drain cleaners which are used to remove grease, hair, tissue paper, etc. Similar to their alkaline versions, such drain openers can dissolve fats and proteins via hydrolysis. Moreover, as concentrated<unk>  has a strong dehydrating property, it can remove tissue paper via dehydrating process as well. Since the<unk>  may react with water vigorously, such<unk> ic drain openers should be added slowly into the pipe to be cleaned.
Sulfuric acid
Silver sulfadiazine
Zinc oxide
Copper naproxen
Salicylic acid
Gadobenic acid
Tienilic acid
Silver diammine fluoride