A process for producing alumina trihydrate includes a digestion step, a separation step, and a precipitation step the separation step including: b1) pretreating a slurry from the digestion step by adding a flocculant to said slurry and mixing the flocculant and the slurry, b2) settling the resulting flocculated slurry in a gravity settler vessel, b3) determining a measured value representative of the concentration of solid particles in the resulting clarified liquor, b4) comparing the measured value with a predetermined threshold, b5) feeding said clarified liquor directly to the precipitation step, while the measured value is less than said predetermined threshold, and b6) redirecting said clarified liquor to the pre-treatment step b1), when the measured value is more than said predetermined threshold. An installation may be configured for operating said process.

Compositions and methods used in the modification of crystallization of aluminum hydroxide from liquor in an aluminum hydroxide production process, such as the Bayer process. More particularly, crystal growth modifier compositions comprising a component of crude corn oil derived from a bioethanol production process and/or a component of biodiesel and methods of using such compositions to modify particle size and distribution of precipitated alumina trihydrate in a precipitation liquor crystallization process.

Compositions and methods used in the modification of crystallization of aluminum hydroxide from liquor in an aluminum hydroxide production process, such as the Bayer process. More particularly, crystal growth modifier compositions comprising a component of crude corn oil derived from a bioethanol production process and/or a component of biodiesel and methods of using such compositions to modify particle size and distribution of precipitated alumina trihydrate in a precipitation liquor crystallization process.

Compositions and methods used in the modification of crystallization of aluminum hydroxide from liquor in an aluminum hydroxide production process, such as the Bayer process. More particularly, crystal growth modifier compositions comprising a component of crude corn oil derived from a bioethanol production process and/or a component of biodiesel and methods of using such compositions to modify particle size and distribution of precipitated alumina trihydrate in a precipitation liquor crystallization process.

A process for producing alumina trihydrate includes a digestion step, a separation step, and a precipitation step the separation step including: b1) pretreating a slurry from the digestion step by adding a flocculant to said slurry and mixing the flocculant and the slurry, b2) settling the resulting flocculated slurry in a gravity settler vessel, b3) determining a measured value representative of the concentration of solid particles in the resulting clarified liquor, b4) comparing the measured value with a predetermined threshold, b5) feeding said clarified liquor directly to the precipitation step, while the measured value is less than said predetermined threshold, and b6) redirecting said clarified liquor to the pre-treatment step b1), when the measured value is more than said predetermined threshold. An installation may be configured for operating said process.