{"id":4307,"date":"2026-05-25T16:42:21","date_gmt":"2026-05-25T08:42:21","guid":{"rendered":"https:\/\/www.jmchemi.com\/?p=4307"},"modified":"2026-05-25T16:42:21","modified_gmt":"2026-05-25T08:42:21","slug":"sodium-hydroxide-applications-preparation-processes-industrial-chain-and-safety-guidelines","status":"publish","type":"post","link":"https:\/\/www.jmchemi.com\/zh\/sodium-hydroxide-applications-preparation-processes-industrial-chain-and-safety-guidelines\/","title":{"rendered":"Sodium Hydroxide: Applications, Preparation Processes, Industrial Chain and Safety Guidelines"},"content":{"rendered":"

Sodium Hydroxide also known as Caustic Soda and Lye, its chemical formula is NaOH with CAS No. 1310-73-2 and molecular weight of approximately 40.00. It is a strong alkaline substance with severe corrosivity.<\/p>\n\n\n\n

Physical and Chemical Properties<\/h2>\n\n\n\n

Pure sodium hydroxide appears as colorless transparent crystals. Industrial-grade products are opaque white crystals due to trace sodium chloride and sodium carbonate impurities, commonly available in lump, flake, granular and rod forms. Key physical parameters are listed below:\u8868\u683c<\/p>\n\n\n\n

Physical Parameter<\/th>Value<\/th><\/tr><\/thead>
Density<\/td>2.130 g\/cm\u00b3<\/td><\/tr>
Melting Point<\/td>318.4\u2103<\/td><\/tr>
Boiling Point<\/td>1390\u2103<\/td><\/tr>
Water Solubility (0\u2103)<\/td>42%<\/td><\/tr>
Water Solubility (20\u2103)<\/td>109%<\/td><\/tr>
Water Solubility (100\u2103)<\/td>347%<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Solubility: Easily soluble in water, ethanol and glycerol; insoluble in ether and acetone.<\/p>\n\n\n\n

Property Description<\/p>\n\n\n\n

    \n
  • Solubility: Highly soluble in water with massive heat release during dissolution. Its aqueous solution is strongly alkaline, featuring astringent taste and slippery texture. Solid sodium hydroxide dissolves readily in glycerol and ethanol, yet insoluble in acetone and ether.<\/li>\n\n\n\n
  • Deliquescence: Solid sodium hydroxide is highly deliquescent in air, absorbing atmospheric moisture and eventually dissolving into liquid.<\/li>\n\n\n\n
  • Hygroscopicity: Solid caustic soda has strong hygroscopicity, while liquid sodium hydroxide has no such property.<\/li>\n<\/ul>\n\n\n\n

    It possesses typical strong alkalinity and undergoes neutralization reaction with acids to generate salt and water. Prone to deterioration by absorbing carbon dioxide in air and forming sodium carbonate, hence sealed and moisture-proof storage is required. It undergoes disproportionation reaction with halogens including chlorine, bromine and iodine, and corrodes certain metals and materials under high temperature.<\/p>\n\n\n\n

    Industrial Chain<\/h2>\n\n\n\n

    Upstream<\/h3>\n\n\n\n

    Raw materials: Crude salt and electric power. Production of one ton of caustic soda consumes 2300-2400 kWh electricity and 1.4-1.6 tons crude salt. Electricity accounts for 50%-60% of production cost, and crude salt takes up 20%-25%.<\/p>\n\n\n\n

    Midstream<\/h3>\n\n\n\n

    Chlor-alkali production. Saturated brine is electrolyzed to produce caustic soda, chlorine and hydrogen simultaneously. Restricted liquid chlorine transportation pushes manufacturers to match PVC production to consume chlorine, realizing balanced production of alkali and chlorine.<\/p>\n\n\n\n

    Downstream Application & Consumption Ratio (2024 Reference)<\/h3>\n\n\n\n
      \n
    • Alumina industry: 28%-32%<\/li>\n\n\n\n
    • Chemical industry: 13%-16%<\/li>\n\n\n\n
    • Printing, dyeing and chemical fiber industry: about 13%<\/li>\n\n\n\n
    • Papermaking industry: about 12%<\/li>\n\n\n\n
    • Water treatment industry: about 9%<\/li>\n\n\n\n
    • New energy (lithium battery materials): emerging growing sector<\/li>\n\n\n\n
    • Others (petroleum, soap, food processing etc.): about 9%<\/li>\n<\/ul>\n\n\n\n

      Preparation Methods<\/h2>\n\n\n\n

      \u8868\u683c<\/p>\n\n\n\n

      Method<\/th>Raw Material<\/th>Core Reaction Condition<\/th>Features<\/th>Current Status<\/th><\/tr><\/thead>
      Causticization Process<\/td>Soda ash & milk of lime<\/td>Around 99-101\u2103<\/td>Simple process, high energy consumption<\/td>Small-scale production<\/td><\/tr>
      Diaphragm Electrolysis<\/td>Saturated crude salt water<\/td>Electrolysis<\/td>Low product purity, environmental pollution risk<\/td>Basically phased out<\/td><\/tr>
      Ion-exchange Membrane Electrolysis<\/td>Refined salt water<\/td>Electrolysis with cation selective membrane<\/td>High purity (\u226599.5%), low energy consumption, pollution-free<\/td>Dominant mainstream, occupying about 95% market share<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

      Application Fields<\/h2>\n\n\n\n

      \u8868\u683c<\/p>\n\n\n\n

      Downstream Industry<\/th>Main Application<\/th>Reference Consumption Ratio<\/th><\/tr><\/thead>
      Alumina<\/td>Bauxite digestion via Bayer process<\/td>28%-32%<\/td><\/tr>
      Chemical Industry<\/td>Synthesis of organic and inorganic chemicals<\/td>13%-16%<\/td><\/tr>
      Printing, Dyeing & Chemical Fiber<\/td>Desizing, scouring, mercerizing and viscose fiber production<\/td>about 13%<\/td><\/tr>
      Papermaking<\/td>Alkaline pulping and cellulose separation<\/td>about 12%<\/td><\/tr>
      Water Treatment<\/td>pH adjustment, heavy metal precipitation and resin regeneration<\/td>about 9%<\/td><\/tr>
      New Energy<\/td>Cathode material production for lithium batteries<\/td>Emerging growth<\/td><\/tr>
      Others<\/td>Petroleum refining, soap making, food processing, glass and enamel manufacturing<\/td>about 9%<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

      Safe Operation and Transportation Storage<\/h2>\n\n\n\n

      Class 8 corrosive dangerous goods. Strong alkalinity causes corrosion to skin, mucous membrane, fabrics and metals.<\/p>\n\n\n\n

      Dissolution Operation: Add caustic soda into water with continuous stirring. Never pour water into caustic soda to avoid boiling splashing caused by intense heat release.<\/p>\n\n\n\n

      Emergency Treatment: Flush contacted skin and eyes with abundant running water for no less than 15 minutes. Do not neutralize with acid to prevent secondary thermal injury. Seek medical treatment timely when necessary.<\/p>\n\n\n\n

      Storage Requirement: Keep sealed and dry, store away from acids and active metal powder to avoid moisture-induced deterioration.<\/p>\n\n\n\n

      <\/p>","protected":false},"excerpt":{"rendered":"

      Sodium Hydroxide also known as Caustic Soda and Lye, its chemical formula is NaOH with CAS No. 1310-73-2 and molecular weight of approximately 40.00. It is a strong alkaline substance with severe corrosivity. Physical and Chemical Properties Pure sodium hydroxide appears as colorless transparent crystals. Industrial-grade products are […]<\/p>","protected":false},"author":1,"featured_media":4308,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_seopress_robots_primary_cat":"","_seopress_titles_title":"","_seopress_titles_desc":"","_seopress_robots_index":"","site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[56],"tags":[],"class_list":["post-4307","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-resources"],"_links":{"self":[{"href":"https:\/\/www.jmchemi.com\/zh\/wp-json\/wp\/v2\/posts\/4307","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.jmchemi.com\/zh\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.jmchemi.com\/zh\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.jmchemi.com\/zh\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.jmchemi.com\/zh\/wp-json\/wp\/v2\/comments?post=4307"}],"version-history":[{"count":1,"href":"https:\/\/www.jmchemi.com\/zh\/wp-json\/wp\/v2\/posts\/4307\/revisions"}],"predecessor-version":[{"id":4309,"href":"https:\/\/www.jmchemi.com\/zh\/wp-json\/wp\/v2\/posts\/4307\/revisions\/4309"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.jmchemi.com\/zh\/wp-json\/wp\/v2\/media\/4308"}],"wp:attachment":[{"href":"https:\/\/www.jmchemi.com\/zh\/wp-json\/wp\/v2\/media?parent=4307"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.jmchemi.com\/zh\/wp-json\/wp\/v2\/categories?post=4307"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.jmchemi.com\/zh\/wp-json\/wp\/v2\/tags?post=4307"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}