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An Innovative Reagent Scheme for Sedimentary
Phosphate Flotation
Yuesheng Gao, Guoxin Wang, Zhengxing Gu, Kevin Rasko, Ben Chen
Arkema-ArrMaz
ABSTRACT: The phosphate rougher flotation in the conventional “Crago” process used to beneficiate Florida
phosphate ore involves a fatty acid type collector and additives of fuel oil/diesel and alkaline. Growing concerns
regarding the cost and environmental impact associated with these additives have prompted the exploration of
alternative flotation reagent schemes. In the present work, the phosphate feed was conditioned with a single
collector, CustoFloat 390, a combination of a fatty acid collector and a surfactant, for rougher flotation, eliminating
the need for additional additives. Comparative analysis of the established process revealed that CustoFloat 390
not only streamlined the flotation process but also delivered comparable or superior performance. Flotation
kinetics were further investigated to assess the efficiency of the proposed scheme. Wettability characterization
was employed to explore the mechanism, revealing that the phosphate feed exhibited enhanced hydrophobicity
when treated with CustoFloat 390. This work contributes novel insights into the sustainable and efficient
flotation of sedimentary phosphate, offering a low-impact solution for environmental preservation.
Keywords: Sedimentary Phosphate, Flotation Schemes, Collectors, Wettability
INTRODUCTION
Plants and animals depend on phosphorus, primarily found
in the form of phosphate minerals in the soil, as an essential
but non-renewable resource(Shen et al., 2019). Due to its
distinctive geological conditions, Florida stands out as the
most prolific sedimentary phosphate region globally and
contributes to more than 60% of the United States phos-
phate rock production(Cook et al., 1990). The extracted
phosphate rock plays a pivotal role in supporting various
industries, including fertilizer production, animal feed
manufacturing, detergent formulation, and the creation of
food and beverage products(Cordell and White, 2013). The
robust phosphate industry in Florida thus serves as a linch-
pin for sustaining agricultural, industrial, and consumer
needs on a national scale.
Phosphate mining in Florida employs a strip-mining
process involving the removal of overburden to access the
phosphate matrix, typically 15 to 25 feet thick. Using a
dragline, the matrix is excavated and deposited into a pit,
where it undergoes a blasting process with a water cannon
to transform it into a slurry. This slurry is subsequently
pumped to the beneficiation plant washer. The beneficia-
tion process is a physical separation method that dissects
the matrix into its constituent parts: approximately one
part phosphate rock, one part clay, and one part sand.
Upon arrival at the washer, a 1 mm screen filters out phos-
phate particles exceeding this size (pebble), leaving behind
sand, clay, and phosphate particles smaller than 1 mm.
Hydrocyclones are employed to further refine the separa-
tion, targeting particles smaller than 0.1 mm. In this step,
clay and phosphate particles below the 0.1 mm threshold
An Innovative Reagent Scheme for Sedimentary
Phosphate Flotation
Yuesheng Gao, Guoxin Wang, Zhengxing Gu, Kevin Rasko, Ben Chen
Arkema-ArrMaz
ABSTRACT: The phosphate rougher flotation in the conventional “Crago” process used to beneficiate Florida
phosphate ore involves a fatty acid type collector and additives of fuel oil/diesel and alkaline. Growing concerns
regarding the cost and environmental impact associated with these additives have prompted the exploration of
alternative flotation reagent schemes. In the present work, the phosphate feed was conditioned with a single
collector, CustoFloat 390, a combination of a fatty acid collector and a surfactant, for rougher flotation, eliminating
the need for additional additives. Comparative analysis of the established process revealed that CustoFloat 390
not only streamlined the flotation process but also delivered comparable or superior performance. Flotation
kinetics were further investigated to assess the efficiency of the proposed scheme. Wettability characterization
was employed to explore the mechanism, revealing that the phosphate feed exhibited enhanced hydrophobicity
when treated with CustoFloat 390. This work contributes novel insights into the sustainable and efficient
flotation of sedimentary phosphate, offering a low-impact solution for environmental preservation.
Keywords: Sedimentary Phosphate, Flotation Schemes, Collectors, Wettability
INTRODUCTION
Plants and animals depend on phosphorus, primarily found
in the form of phosphate minerals in the soil, as an essential
but non-renewable resource(Shen et al., 2019). Due to its
distinctive geological conditions, Florida stands out as the
most prolific sedimentary phosphate region globally and
contributes to more than 60% of the United States phos-
phate rock production(Cook et al., 1990). The extracted
phosphate rock plays a pivotal role in supporting various
industries, including fertilizer production, animal feed
manufacturing, detergent formulation, and the creation of
food and beverage products(Cordell and White, 2013). The
robust phosphate industry in Florida thus serves as a linch-
pin for sustaining agricultural, industrial, and consumer
needs on a national scale.
Phosphate mining in Florida employs a strip-mining
process involving the removal of overburden to access the
phosphate matrix, typically 15 to 25 feet thick. Using a
dragline, the matrix is excavated and deposited into a pit,
where it undergoes a blasting process with a water cannon
to transform it into a slurry. This slurry is subsequently
pumped to the beneficiation plant washer. The beneficia-
tion process is a physical separation method that dissects
the matrix into its constituent parts: approximately one
part phosphate rock, one part clay, and one part sand.
Upon arrival at the washer, a 1 mm screen filters out phos-
phate particles exceeding this size (pebble), leaving behind
sand, clay, and phosphate particles smaller than 1 mm.
Hydrocyclones are employed to further refine the separa-
tion, targeting particles smaller than 0.1 mm. In this step,
clay and phosphate particles below the 0.1 mm threshold