{"id":317,"date":"2026-07-08T15:36:52","date_gmt":"2026-07-08T07:36:52","guid":{"rendered":"https:\/\/www.rubri.cn\/indie_testimonial\/v2-case-7\/"},"modified":"2026-10-27T07:18:13","modified_gmt":"2026-10-26T23:18:13","slug":"waste-acid-recovery-titanium-dioxide-480m3d","status":"publish","type":"indie_testimonial","link":"https:\/\/www.rubri.cn\/en\/indie_testimonial\/waste-acid-recovery-titanium-dioxide-480m3d\/","title":{"rendered":"Diffusion dialysis (DD) used in a 480 m\u00b3\/day waste acid recovery treatment project for a titanium dioxide enterprise"},"content":{"rendered":"<p>Diffusion dialysis (DD) is used in a 480 m\u00b3\/day waste acid recovery treatment project for a titanium dioxide enterprise to show the treatment scale and operating indicators of this technical route in similar projects.<\/p>\n<h2>Key indicators<\/h2>\n<ul>\n<li>Feed acid: 24%, ferrous content 45000 ppm<\/li>\n<li>Product acid \u226522%, ferrous content 500 ppm<\/li>\n<li>Treatment capacity: 480 m\u00b3\/day<\/li>\n<li>Equipment: 93 units TWDD-128-400A<\/li>\n<\/ul>\n<h2>Project background<\/h2>\n<p>In sulfate-process titanium dioxide production, the hydrolysis and washing stages generate large amounts of sulfuric acid-containing waste acid, which also contains metal salts such as ferrous sulfate.<\/p>\n<p>The waste acid is generated in large quantities and at relatively high concentration; neutralization disposal costs are high, and both sulfuric acid and iron salts have separate recovery value.<\/p>\n<p>The project is designed on the premise of large-scale continuous operation, with the goal of stably recovering sulfuric acid and reducing the treatment load on the subsequent neutralization stage.<\/p>\n<h2>Process route<\/h2>\n<ul>\n<li>Diffusion dialysis (DD) is used, driven by concentration difference to separate free sulfuric acid from metal salts.<\/li>\n<li>TWDD-128-400A diffusion dialysis stacks are configured and grouped in parallel according to treatment scale to form a continuous treatment line.<\/li>\n<li>Filtration and constant-temperature units are installed at the feed to reduce particulate fouling and maintain stable membrane flux.<\/li>\n<li>Recovered acid is returned to the acid hydrolysis or leaching process, and the salt-containing residual liquid enters subsequent treatment or by-product recovery.<\/li>\n<\/ul>\n<h2>Configuration scale<\/h2>\n<ul>\n<li>Treatment capacity: 480 m\u00b3\/day.<\/li>\n<li>Membrane stack equipment: 93 units (model TWDD-128-400A).<\/li>\n<\/ul>\n<h2>Illustrative materials<\/h2>\n<div class=\"iw-media-grid\">\n<figure><img decoding=\"async\" width=\"763\" height=\"536\" src=\"\/wp-content\/uploads\/2026\/07\/v2-dff236e0dedb.jpeg\" class=\"attachment-large size-large\" alt=\"\u6269\u6563\u6e17\u6790\u7528\u4e8e\u67d0\u949b\u767d\u7c89\u4f01\u4e1a480\u65b9\/\u5929\u56de\u6536\u5e9f\u9178\u5904\u7406\u9879\u76ee\" loading=\"lazy\" \/><figcaption>Illustration of diffusion dialysis (DD) used in a 480 m\u00b3\/day waste acid recovery treatment project for a titanium dioxide enterprise<\/figcaption><\/figure>\n<\/div>","protected":false},"featured_media":134,"menu_order":70,"template":"","meta":{"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 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