Precipitation selectivity of boron compounds from slags

Dynamic Oxidation of the Ti-bearing Blast Furnace Slag

“…The perovskite is composed of Ti 4ϩ , and the titanaugite and Ti-rich diopside are composed of Ti 2ϩ and Ti 3ϩ . 1) Based on several studies and practices [5][6][7][8][9][10][11] on the slag in a pilot plant, by blowing air to the molten slag during the dynamic oxidation process, (Ti 2ϩ ) and (Ti 3ϩ ) in the slag could be oxidized to (Ti 4ϩ ), most of the Ti component was enriched into the perovskite phase, the growth of the perovskite phase and the drop of metallic Fe droplets proceeded due to the dynamic oxidation of the molten slag. The perovskite phase can be separated from the slag by mineral dressing method, and this product can be utilized as raw material of the titanium pigment industry.…”

Separation of Olivine Crystals and Borate Containing Slag from CaO–SiO₂–B₂O₃–MgO–Al₂O₃ System by Utilizing Super-Gravity

“…Considering olivine was the first precipitate from boronbearing slag with temperature decreasing based on B 2 O 3 -MgO-SiO 2 phase diagram, while kotoite and suanite precipitated at lower temperatures and uniformly distributed among the first precipitated olivine, [5][6][7][8][9][10][11] the separation of olivine precipitate and borate containing slag thus would be another feasible choice for recovering boron from the slag. Consequently, the precipitation behavior of olivine in CaO-SiO 2 -B 2 O 3 -MgO-Al 2 O 3 system was investigated, and then the separation of olivine crystals and borate containing slag melt by utilizing super-gravity was conducted in current study, which under the inspiration of successful application of super-gravity on some other melts.…”

“…2,3) Fortunately, many novel technical methods have been proposed for recovering boron from the slag, mainly including the acid leaching process, 4,5) and the precipitation and crystallization method. 6,7) Sui proposed 7) that the efficiency of boron extraction from boron-bearing slag was related to the precipitating amount of suanite (Mg 2 B 2 O 5 ) and kotoite (Mg 3 B 2 O 6 ), and the optimum precipitating temperature of boron appeared at 1 373 K. Xia 8) suggested further that the temperature range of 1 473 K-1 373 K was beneficial for the nucleation and growth of suanite precipitate. Liu 9) proposed that the boron extraction rate in a low temperature range reduced with the decrease of cooling-rate in a high temperature range.…”

Influence of P2O5 on Crystallization of V-concentrating Phase in V-bearing Steelmaking Slag

“…4,5) Another process of selective enrichment which handles lower content of element or compound in slag has been proposed and used in Ti-bearing blast-furnace slag for Ti and in B-bearing slag for B. 6,7) Our previous studies have found that when V-bearing steelmaking slag with 2.4 wt% P 2 O 5 was doped with 20 wt% Al 2 O 3 , most of V 2 O 5 in the slag was concentrated in whitlockite, 8,9) and V-concentrating phase grew with holding time at crystallization temperature of 1 648 K. But the study of influence of chemical composition, for example, P 2 O 5 , on crystallization of V-concentrating phase has not found anywhere.…”