{"id":6885,"date":"2026-08-06T14:59:48","date_gmt":"2026-08-06T22:59:48","guid":{"rendered":"https:\/\/changyupump.com\/?p=6885"},"modified":"2026-08-06T15:00:54","modified_gmt":"2026-08-06T23:00:54","slug":"gypsum-slurry-pump","status":"publish","type":"post","link":"https:\/\/changyupump.com\/es\/blog\/gypsum-slurry-pump\/","title":{"rendered":"Bomba de Lodos de Yeso: Gu\u00eda Completa de Selecci\u00f3n y Materiales"},"content":{"rendered":"\n

Quick Answer<\/h2>\n\n\n\n

Selecting the right gypsum slurry pump<\/strong> requires managing the crystallization that occurs when dissolved gypsum precipitates during temperature changes or shutdowns, choosing materials that resist both the abrasive wear of gypsum crystals and the often acidic slurry chemistry, and implementing seal flush and shutdown procedures that prevent crystal formation at mechanical seal faces. Key quantified selection factors:<\/p>\n\n\n\n

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  1. Gypsum crystallization behavior<\/strong>: Gypsum solubility increases with temperature \u2014 when slurry cools from 60\u00b0C to 20\u00b0C, dissolved gypsum can precipitate rapidly, forming abrasive crystals on seal faces and impeller surfaces. A 10\u201315 minute clean water flush before shutdown removes residual slurry and prevents crystallization.<\/li>\n\n\n\n
  2. Material selection for gypsum service<\/strong>: Although gypsum itself is soft (Mohs 2), gypsum slurry often contains residual limestone (Mohs 3\u20134) and fly ash particles (silica, Mohs 7) that contribute significantly to abrasive wear. UHMW-PE linings resist both the chemical environment and the abrasive solids, providing 6\u20138 years of service in FGD gypsum applications.<\/li>\n\n\n\n
  3. Seal protection from crystallization<\/strong>: Gypsum crystallization at mechanical seal faces is the most common cause of premature pump failure in gypsum service. API Plan 32 external flush with clean water prevents slurry from contacting seal faces. A shutdown flush removes residual slurry before cooling triggers crystallization.<\/li>\n\n\n\n
  4. Impeller design for gypsum slurries<\/strong>: Semi-open impellers with wide flow passages prevent the solids accumulation that occurs with enclosed designs when gypsum particles settle during intermittent operation. Vortex impellers provide additional protection where solids concentration varies widely.<\/li>\n<\/ol>\n\n\n\n

    Gypsum slurry presents a deceptive pumping challenge. The gypsum particles are relatively soft compared to mineral ores. But the dominant threat is chemical rather than purely mechanical: gypsum dissolves when warm and crystallizes when cool. Every time a pump shuts down, the slurry remaining in the casing begins to cool. Dissolved gypsum precipitates from the cooling solution \u2014 coating impeller passages, settling in the volute, and most critically, forming abrasive crystals between mechanical seal faces. When the pump restarts, these crystals act as a grinding compound that destroys the seal within days.<\/p>\n\n\n\n

    \"Gypsum<\/figure>\n\n\n\n

    Changyu Pump has manufactured wear and corrosion-resistant pumps for FGD, phosphoric acid, and gypsum processing applications for over two decades. This guide covers the crystallization mechanisms, material selection, seal protection, and operating procedures that determine whether a gypsum slurry pump delivers reliable service or becomes a recurring maintenance problem.<\/p>\n\n\n\n

    1. Why Is Pumping Gypsum Slurry So Deceptive?<\/h2>\n\n\n\n

    Gypsum slurry combines a relatively soft abrasive with an aggressive chemical precipitation mechanism. Understanding both is essential for correct pump specification.<\/p>\n\n\n\n

    The Abrasive Reality<\/h3>\n\n\n\n

    Although pure gypsum<\/a> registers only Mohs 2 \u2014 softer than a fingernail \u2014 gypsum slurry in industrial service is rarely pure. In FGD applications, the slurry contains unreacted limestone particles (Mohs 3\u20134). In many plants, fly ash carryover introduces silica particles (Mohs 7) into the absorber slurry. These harder particles contribute significantly to the abrasive wear that attacks pump casings and impellers. The wear rate is compounded by the acidic slurry chemistry \u2014 gypsum slurry in FGD and phosphoric acid applications has a pH ranging from 1\u20136, which accelerates corrosion of many metals.<\/p>\n\n\n\n

    The Crystallization Mechanism<\/h3>\n\n\n\n

    The solubility of gypsum in water is temperature-dependent. At the typical operating temperature of FGD absorber slurry (50\u201370\u00b0C), gypsum remains largely in solution. But as the slurry cools \u2014 whether during a planned shutdown, a pump changeover, or simply in the stagnant fluid within an idle pump casing \u2014 the dissolved gypsum precipitates from solution. These newly formed crystals deposit on any surface they contact: impeller vanes, volute walls, and mechanical seal faces.<\/p>\n\n\n\n

    This crystallization process has two triggers relevant to pump operation:<\/p>\n\n\n\n