This topic is discussed in the following articles:
APPLICATIONS
alkali refining
Fat and oil processing: Alkali refining
Many of these can be removed by treating fats at 40° to 85° C (104° to 185° F) with an aqueous solution of caustic soda (sodium hydroxide) or soda ash (sodium carbonate). The refining may be done in a tank (in which case it is called batch or tank refining) or in a continuous system. In batch refining, the aqueous emulsion of soaps formed from free fatty acids, along with other...
alkaline digestion of monazite
Thorium processing: Acidic and alkaline digestion
In alkaline digestion, finely ground monazite sand is carefully treated with a concentrated NaOH solution at 138 °C (280 °F) to produce a solid hydroxide product. Any one of several mineral acids is then used to dissolve this solid residue. For example, treatment with hydrochloric acid yields a solution of thorium and rare earth chlorides. Conventionally, thorium is partially separated...
aluminum refining
Aluminum processing: Refining the ore
In the first step, bauxite is ground, slurried with a solution of caustic soda (sodium hydroxide), and pumped into large pressure tanks called digesters, where the ore is subjected to steam heat and pressure. The sodium hydroxide reacts with the aluminous minerals of bauxite to form a saturated solution of sodium aluminate; insoluble impurities, called red mud, remain in suspension and are...
mercerization
Mercerization
The treatment consists of immersing the yarn or fibre in a solution of sodium hydroxide (caustic soda) for short periods of time, usually less than four minutes. The material is then treated with water or acid to neutralize the sodium hydroxide. If the material is held under tension during this stage, it is kept from shrinking appreciably; if no tension is applied, the material may shrink by as...
paper production
Papermaking: Chemical wood pulp
In 1851 paper pulp was experimentally produced from wood by cooking it with caustic soda at elevated temperature and pressure. Although this soda process attained commercial importance, soda pulp was of relatively low strength; and use of the process was limited to manufacturing filler pulps from hardwood, which were then mixed with a stronger fibre for printing papers. Because this process...
soap production and saponification
Soap and detergent: Soap manufacturing processes and products
Hot caustic alkali solution, such as caustic soda (sodium hydroxide), acts on natural fats or oils, such as tallow or vegetable oil, to produce sodium fatty acid salt (soap) and glycerin (or glycerol). This saponification reaction is the basis for all soapmaking. If industrially produced fatty acids are used in place of natural fats or oils, the reaction with caustic soda yields soap and water...
Soap and detergent: Processes
Following this, caustic soda solution is used to neutralize the acidic products of the reaction. Figure 1 shows the principles of this process.
EXTRACTION AND PROCESSING
acid–base reactants
Acid–base reaction
Apart from their theoretical interest, acids and bases play a large part in industrial chemistry and in everyday life. Sulfuric acid and sodium hydroxide are among the products manufactured in largest amounts by the chemical industry, and a large percentage of chemical processes involve acids or bases as reactants or as catalysts. Almost every biological chemical process is closely bound up...
alkali
Alkali
The manufacture of industrial alkali usually refers to the production of soda ash (Na2CO3; sodium carbonate) and caustic soda (NaOH; sodium hydroxide). Other industrial alkalies include potassium hydroxide, potash, and lye. The production of a vast range of consumer goods depends on the use of alkali at some stage. Soda ash and caustic soda are essential to the production...
preparation from sodium chloride
Chemical industry: Electrolytic process
...breaking down of a compound in solution into its elements by means of an electric current, is used to bring about a chemical change. Electrolysis of sodium chloride can lead to chlorine and either sodium hydroxide (if the NaCl was in solution) or metallic sodium (if the NaCl was fused). Sodium hydroxide, an alkali like sodium carbonate, in some cases competes with it for the same applications,...
Chemical industry: Commercial preparation
The chlor-alkali industry—in which chlorine and caustic soda (sodium hydroxide) are produced simultaneously by electrolytic decomposition of salt (sodium chloride)—has become the principal source of chlorine during the 20th century. As noted earlier, in the two important versions of the electrolytic process, brine is the electrolyte (in which the passage of electric current occurs...
nomenclature of ionic compounds
Chemical compound: Ionic compounds containing polyatomic ions
Naming ionic compounds that contain polyatomic ions is similar to naming binary ionic compounds. For example, the compound NaOH is called sodium hydroxide, because it contains the Na+ (sodium) cation and the OH− (hydroxide) anion. As in binary ionic compounds, when a metal that can form multiple cations is present, a Roman numeral is required to specify the charge on...
nucleophilic substitution
Organohalogen compound: Nucleophilic substitution
...is normally an ionic sodium or a potassium salt (Na+Y−or K+Y−). A specific example of a nucleophilic substitution is the reaction of sodium hydroxide and benzyl chloride:
sodium compounds
Sodium (Na): Principal compounds
Sodium hydroxide (NaOH) is a corrosive, white crystalline solid that readily absorbs moisture until it dissolves. Commonly called caustic soda, or lye, sodium hydroxide is the most widely used industrial alkali. It is highly corrosive to animal and vegetable tissue. The alkaline solutions it forms when dissolved in water neutralize acids in various commercial processes: in petroleum refining,...
หัวข้อนี้จะกล่าวถึงในบทความต่อไปนี้:โปรแกรมประยุกต์โรงกลั่นอัลคาไลไขมันและน้ำมันในการประมวลผล: โรงกลั่นอัลคาไลมากสามารถเอาออก โดยการรักษาไขมันที่ 40° ถึง 85° C (104° ถึง 185° F) กับการละลายของโซดาไฟ (โซเดียมไฮดรอกไซด์) หรือโซดาแอช (โซเดียมคาร์บอเนต) โรงกลั่นอาจจะทำ ในถัง (ในกรณีที่เรียกว่าชุดหรือกลั่นถัง) หรือ ในระบบอย่างต่อเนื่อง ในชุดงานโรงกลั่น อิมัลชันอควีของสบู่เกิดจากกรดไขมันอิสระ พร้อมกัน...ย่อยอาหารด่างของโมนาไซด์ประมวลผลทอเรียม: ย่อยอาหารกรด และด่างในด่างย่อยอาหาร ประณีตพื้นทรายโมนาไซด์อย่างระมัดระวังถือว่า มีโซลูชัน NaOH เข้มข้นที่ 138 ° C (280 ° F) การผลิตผลิตภัณฑ์แข็งไฮดรอกไซด์ กรดแร่หลายหนึ่งแล้วใช้ละลายสารตกค้างนี้แข็ง ตัวอย่าง บำบัด ด้วยกรดไฮโดรคลอริกทำให้โซลูชันของคลอไรด์ทอเรียมและธาตุหายาก ดี ทอเรียมบางส่วนแยก...อลูมิเนียมปรับประมวลผลอลูมิเนียม: กลั่นแร่ในขั้นแรก แร่อะลูมิเนียม พื้น slurried กับโซลูชันของโซดาไฟ (โซเดียมไฮดรอกไซด์), และสูบเข้าสู่ถังความดันขนาดใหญ่ที่เรียกว่า digesters ที่ซึ่งแร่ขึ้นอยู่กับไอน้ำความร้อนและความดัน ไฮดรอกไซด์โซเดียมทำปฏิกิริยากับแร่ aluminous ของแร่อะลูมิเนียมเพื่อแก้ปัญหาการอิ่มตัวของโซเดียม aluminate ขึ้น เรียกว่าโคลนแดง ยังคงอยู่ในระบบกันสะเทือน และมี...mercerizationMercerizationThe treatment consists of immersing the yarn or fibre in a solution of sodium hydroxide (caustic soda) for short periods of time, usually less than four minutes. The material is then treated with water or acid to neutralize the sodium hydroxide. If the material is held under tension during this stage, it is kept from shrinking appreciably; if no tension is applied, the material may shrink by as...paper productionPapermaking: Chemical wood pulpIn 1851 paper pulp was experimentally produced from wood by cooking it with caustic soda at elevated temperature and pressure. Although this soda process attained commercial importance, soda pulp was of relatively low strength; and use of the process was limited to manufacturing filler pulps from hardwood, which were then mixed with a stronger fibre for printing papers. Because this process...soap production and saponificationSoap and detergent: Soap manufacturing processes and productsHot caustic alkali solution, such as caustic soda (sodium hydroxide), acts on natural fats or oils, such as tallow or vegetable oil, to produce sodium fatty acid salt (soap) and glycerin (or glycerol). This saponification reaction is the basis for all soapmaking. If industrially produced fatty acids are used in place of natural fats or oils, the reaction with caustic soda yields soap and water...Soap and detergent: ProcessesFollowing this, caustic soda solution is used to neutralize the acidic products of the reaction. Figure 1 shows the principles of this process.EXTRACTION AND PROCESSINGacid–base reactantsAcid–base reactionApart from their theoretical interest, acids and bases play a large part in industrial chemistry and in everyday life. Sulfuric acid and sodium hydroxide are among the products manufactured in largest amounts by the chemical industry, and a large percentage of chemical processes involve acids or bases as reactants or as catalysts. Almost every biological chemical process is closely bound up...alkaliAlkaliThe manufacture of industrial alkali usually refers to the production of soda ash (Na2CO3; sodium carbonate) and caustic soda (NaOH; sodium hydroxide). Other industrial alkalies include potassium hydroxide, potash, and lye. The production of a vast range of consumer goods depends on the use of alkali at some stage. Soda ash and caustic soda are essential to the production...preparation from sodium chlorideChemical industry: Electrolytic process...breaking down of a compound in solution into its elements by means of an electric current, is used to bring about a chemical change. Electrolysis of sodium chloride can lead to chlorine and either sodium hydroxide (if the NaCl was in solution) or metallic sodium (if the NaCl was fused). Sodium hydroxide, an alkali like sodium carbonate, in some cases competes with it for the same applications,...Chemical industry: Commercial preparationThe chlor-alkali industry—in which chlorine and caustic soda (sodium hydroxide) are produced simultaneously by electrolytic decomposition of salt (sodium chloride)—has become the principal source of chlorine during the 20th century. As noted earlier, in the two important versions of the electrolytic process, brine is the electrolyte (in which the passage of electric current occurs...nomenclature of ionic compoundsChemical compound: Ionic compounds containing polyatomic ionsNaming ionic compounds that contain polyatomic ions is similar to naming binary ionic compounds. For example, the compound NaOH is called sodium hydroxide, because it contains the Na+ (sodium) cation and the OH− (hydroxide) anion. As in binary ionic compounds, when a metal that can form multiple cations is present, a Roman numeral is required to specify the charge on...nucleophilic substitutionOrganohalogen compound: Nucleophilic substitution...is normally an ionic sodium or a potassium salt (Na+Y−or K+Y−). A specific example of a nucleophilic substitution is the reaction of sodium hydroxide and benzyl chloride:sodium compoundsSodium (Na): Principal compoundsSodium hydroxide (NaOH) is a corrosive, white crystalline solid that readily absorbs moisture until it dissolves. Commonly called caustic soda, or lye, sodium hydroxide is the most widely used industrial alkali. It is highly corrosive to animal and vegetable tissue. The alkaline solutions it forms when dissolved in water neutralize acids in various commercial processes: in petroleum refining,...
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