Recovery of Phosphate From Unused Resources

Abstract

The recovery of aqueous phosphate from a model solution consisting of NH 4 + , NO 2 and NO 3-, which are contained in a surplus that phosphate in rivers in Tokushima Prefecture, Japan, using boehmite together with the elution behaviors of phosphate from dephosphorization slag using various eluates were examined. The recovery of aqueous phosphate using boehmite was not influenced by the coexistence of those nitrogen-containing contaminants under various pH conditions. For the elution behaviors of phosphate from dephosphorization slag, it was found that aqueous HNO 3 among various acidic and basic solutions was a suitable solution as an eluate. Present study suggests that the employment of the unused resources such as aqueous phosphate in rivers and phosphate in the dephosphorization slag can be used as a possible candidate as a new raw material for rare phosphate.

Recovery and Enrichment of Aqueous Phosphate From the Slag Released by a Chemical Factory

“…To confirm the element distribution with the exception of carbon species, the solid was also analyzed using an electron probe micro analyzer (EPMA; EDAX, Phoenix). To examine the removal of aqueous Fe 3+ with CaHAp, an aqueous solution (100 ml), to which a known quantity of Fe(NO 3 ) 3 . 9H 2 O (Wako) had been added, was stirred at 120 rpm in a constant temperature bath at 293 K for 10 min.…”

“…To confirm the content of the various elements in the brown powder, 0.14 g of the powder was dissolved in aq. HNO 3 . Since 93% of the brown powder could be dissolved in aq.…”

“…Since, as shown in TABLE 1, the slag contains various elements, it is expected that other elements are simultaneously eluted together with phosphate from the slag. Since the slag contains mostly Fe 3+ and Ca 2+ together with PO 4 3-, the elution behaviors of these cations were examined using HNO 3 . It should be noted that the slag after the calcination was used for this purpose.…”

“…In our laboratory, phosphate was separated from dephosphorization slag using a wet-processing method. 3 In the present study, the slag released from a chemical factory was recognized as another unused phosphorus resource and the elution behaviors of phosphate from the slag using various aqueous solutions were examined. The slag is produced by adding phosphoric acid as a neutralizer to the basic waste flowing from a chemical factory.…”

Fundamental Experiment to Extract Phosphorous Selectively from Steelmaking Slag by Leaching

“…Based on the results shown by Miki et al, 2) the solubility of C 2 S is much greater than that of C 3 P in sea water, and the solubility of both phases decreases with an increase in pH. S. Sugiyama et al 3,4) has investigated the elution of phosphorus from industrial steelmaking slag and revealed that phosphorus was able to be easily eluted using 1 mol/L-HNO 3 solution. However, by their condition, elution rates of Fe 3+ was comparably high as that of PO 4 3-, and the separation of Fe 3+ in the solution was necessary to recover phosphorus.…”