• US7396474B2 - Dual injection of two polymeric filtration ...

    A process to improve the polymeric filtration aid performance used in removal of gypsum from phosphoric acid/gypsum slurry. A synergistic effect has been observed by using a Dual Injection method. This method more specifically involves using two polymers (A & B) of different chemistry and injecting into slurry at a different time. The polymer chemistry of filtration aid A is selected from the ...

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  • Dual injection of two polymeric filtration aids for gypsum ...

    Jul 08, 2008· A process to improve the polymeric filtration aid performance used in removal of gypsum from phosphoric acid/gypsum slurry. A synergistic effect has been observed by using a Dual Injection method. This method more specifically involves using two polymers (A & B) of different chemistry and injecting into slurry at a different time.

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  • EP2279151A1 - Method of purifying gypsum - Google Patents

    The present invention relates to a method of purifying flue gas desulfurization (FGD) gypsum. The method is characterized by comprising the steps of a) providing an aqueous slurry containing said FGD gypsum, b) passing said aqueous slurry to a magnetic separator, and c) contacting the FGD gypsum to be purified with a solution containing an acid and having pH below 5 in an acid washing step.

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  • Improving Gypsum Slurry Filtration in the Production of ...

    The filtration rate of the gypsum slurry is increased by 4.8 times, and the filter cake moisture is reduced by 11.79%, with the addition of PADB. The mechanism of filtration aiding was also researched, which shows that PADB can change the mean diameter of crystals and agglomerate the tiny crystals; PADB can decrease the surface tension of the filter liquor and enhance the hydrophobicity of the gypsum.

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  • US20120171099A1 - Phosphoric acid production gypsum ...

    A method for minimizing the addition of water to a phosphoric acid production process is described. The method uses phosphoric acid to make down a flocculant that is added to the process in order to promote filtration or clarification of crude phosphoric acid. Preferably, the phosphoric acid is a crude, clarified phosphoric acid that is recycled from the phosphoric acid production process itself.

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  • Gypsum Slurry Improving - edithbeeldend.nl

    A method for improving gypsum slurry filtration in the production of wet process phosphoric acid wherein an effective amount of carboxylic-type polymer having a portion of sulfonic functionality is used as the filtration aid Preferred polymers are high molecular weight polymers of acrylic acid and acrylamido methylpropyl sulfonic acid

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  • SEPARATION GYPSUM DEWATERING AT THE HIGHEST LEVEL

    Washing the flue gas with a limestone slurry became established as the most successful method. Efficient dewatering of the gypsum slurry provides an end product with good reusability. High purity levels and lowest residual moisture are best obtained using …

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  • METHOD FOR IMPROVING GYPSUM/PHOSPHORIC ACID SLURRY ...

    Abstract: A chemical process to improve the filtration performance for the removal of gypsum from phosphoric acid/gypsum slurry using a filtration aid that is selected from a class of polymers, lower molecular weight anionic polyelectrolytes, which previously have not been used for this application.

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  • US5211928A - Method of improving gypsum slurry filtration ...

    A method for improving gypsum slurry filtration in the production of wet process phosphoric acid wherein an effective amount of carboxylic-type polymer having a portion of sulfonic functionality is used as the filtration aid. Preferred polymers are high molecular weight polymers of acrylic acid and acrylamido methylpropyl sulfonic acid.

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  • Increasing the Filtration Rate of Phosphor-gypsum by Using ...

    Peer-review under responsibility of the Scientific Committee of SYMPHOS 2015 doi: 10.1016/j.proeng.2016.02.073 ScienceDirect “SYMPHOS 2015†, 3rd International Symposium on Innovation and Technology in the Phosphate Industry Increasing the filtration rate of phosphor-gypsum by using mineral additives Slimane Manar* OCP SA, Morocco ...

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  • Method of improving gypsum slurry filtration in the ...

    May 18, 1993· A method for improving gypsum slurry filtration in the production of wet process phosphoric acid wherein an effective amount of carboxylic-type polymer having a portion of sulfonic functionality is used as the filtration aid. Preferred polymers are high molecular weight polymers of acrylic acid and acrylamido methylpropyl sulfonic acid.

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  • Improving Gypsum Slurry Filtration in the Production of ...

    The copolymer was used for the filtration aiding in the wet process phosphoric acid. The filtration rate of the gypsum slurry is increased by 4.8 times, and the filter cake moisture is reduced by 11.79%, with the addition of PADB.

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  • Increasing the Filtration Rate of Phosphor-gypsum by Using ...

    After leaching, the slurry is filtered and counter-current washed to separate the acid from the phosphogypsum cake. Filtration operation represents a bottleneck in the wet-process phosphoric acid industry. Using the same filter area, the production capacity with lower operating costs can be achieved if the filtration rate is increased.

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  • System And Method For Producing A Gypsum Slurry ... - The Lens

    The method of claim 11, comprising receiving the gypsum slurry from a gypsum slurry production system that comprises: a conveyor providing gypsum, a pump providing a fluid, a mixing device configured to mix the gypsum provided by the conveyor with the fluid provided by the pump to produce the gypsum slurry, and a slurry pump configured to pump ...

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  • Method for preparing a nano-calcium carbonate slurry from ...

    Apr 26, 2013· The present invention discloses a process for producing a nano calcium carbonate slurry from a feedstock of waste gypsum, wherein: an aqueous gypsum slurry of the feedstock is mixed with ammonia water by stirring; with CO2 injected in the slurry is under continuous stirring until the calcium sulfate in the waste gypsum is completely carbonated into nano calcium carbonate; after filtration, …

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  • Method for separating calcium carbonate and gypsum - …

    Nov 19, 2015· A method for separating a suspension containing gypsum granules and calcium carbonate granules and an aqueous solution, wherein the aqueous solution comprises at least one sodium salt, wherein the aqueous solution has a sodium ion concentration of at least 3 g/L and wherein such method comprises a step of separation by flotation using a collector for the gypsum granules, …

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  • The Florida Institute of Phosphate Research was created in ...

    The Florida Institute of Phosphate Research is acknowledged for sponsoring this study ... Attempts to improve the filtration rate using polymers as “filter aids” have been ... The polymer in such cases is added just prior to the filtration step to flocculate the fine gypsum particles. The improvement in filtration by filter aids is usually ...

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