scholarly journals Treatment of Secondary Dust Produced in Rotary Hearth Furnace through Alkali Leaching and Evaporation–Crystallization Processes

Processes ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 396
Author(s):  
Shuang Liang ◽  
Xiaoping Liang ◽  
Qian Tang
Keyword(s):  
Crystallization Process ◽  
Rotary Hearth Furnace ◽  
Hearth Furnace ◽  
Cooling Temperature ◽  
Solid Ratio ◽  
Evaporation Temperature ◽  
Optimum Quantity ◽  
Evaporation Ratio ◽  
Alkali Leaching ◽  
Volume Evaporation

This paper presents the results of an experimental study on the extraction of KCl and the improvement of the zinc grade of secondary dust obtained from rotary-hearth-furnace secondary dust (RHF secondary dust) using alkali leaching (Na2CO3 solution) and evaporation–crystallization processes. The effects of the liquid–solid ratio and Na2CO3 content on the element leaching ratio in the alkali leaching process, as well as the effects of the volume–evaporation ratio and cooling temperature on KCl extraction in the evaporation–crystallization process, were investigated. The results showed that the optimum liquid–solid ratio was 6:1, and the optimum quantity of Na2CO3 was 1.5 times the basic quantity. The recovery ratio of zinc reached 95.23%, and the leaching ratio of K reached 79.01%. The experimental results of the evaporation–crystallization process demonstrated that the evaporation temperature was 80 °C, the volume evaporation ratio was 50%, the cooling temperature was 25 °C, and the mass fraction of K2O in the obtained crystals was 58.99%.

Producing ZnO nano powder from rotary hearth furnace dust along with Pb removal

2021 ◽  
pp. 108496
Author(s):  
Dianchun Ju ◽  
Haiwei Yao ◽  
Han Ma ◽  
Rui Mao ◽  
Jiayong Qiu ◽  
...  
Keyword(s):  
Rotary Hearth Furnace ◽  
Hearth Furnace ◽  
Nano Powder

An effective separation process of arsenic, lead, and zinc from high arsenic-containing copper smelting ashes by alkali leaching followed by sulfide precipitation

2020 ◽  
Vol 38 (11) ◽  
pp. 1214-1221
Author(s):  
Yuhui Zhang ◽  
Xiaoyan Feng ◽  
Bingjie Jin
Keyword(s):  
Separation Efficiency ◽  
Separation Process ◽  
Copper Smelting ◽  
Solid Ratio ◽  
Effective Separation ◽  
Lead And Zinc ◽  
Valuable Metals ◽  
Alkali Leaching ◽  
Sulfide Precipitation ◽  
High Arsenic

Separation of arsenic and valuable metals (Pb, Zn, Cu, Bi, Sn, In, Ag, Sb, etc.) is a core problem for effective utilization of high arsenic-containing copper smelting ashes (HACSA). This study developed an effective separation process of arsenic, lead, and zinc from HACSA via alkali leaching followed by sulfide precipitation. The separation behaviors and optimum conditions for alkali leaching of arsenic and sulfide precipitation of lead and zinc were established respectively as follows: NaOH concentration 3.81 M; temperature 80°C; time 90 minutes; liquid-to-solid ratio 4:1; agitation speed 450 revolutions/minute (r/min) and 2.0 times of theoretical quantity of sodium sulfide (Na2S); temperature 70°C; and time 60 minutes. The results indicated that the leaching rates of As, Pb, and Zn were 92.4%, 36.9% and 13.4%, respectively. More than 99% of lead and zinc were precipitated from the alkali leachate. The scanning electron microscopy/energy dispersive X-ray spectroscopy study confirmed that arsenic was dissolved from HACSA into the alkali leachate. Furthermore, lead and zinc were precipitated as sulfides from the alkali leachate. The proposed process was a good technique for separation of arsenic and enrichment of valuable metals for further centralized treatment separately. It provided high separation efficiency of arsenic and valuable metals, as well as low environmental pollution.

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