張 敏, 沈家華, 劉東云
(1.廣西大學 資源與冶金學院, 廣西 南寧 530004; 2.廣西理工科學實驗中心, 廣西 南寧 530004)
引流介質(zhì)充填強化旋流-靜態(tài)浮選過程的研究
張 敏1,2, 沈家華1, 劉東云1
(1.廣西大學 資源與冶金學院, 廣西 南寧 530004; 2.廣西理工科學實驗中心, 廣西 南寧 530004)
介質(zhì)充填可有效改善浮選環(huán)境.傳統(tǒng)篩板僅是部分抑制旋流,填料充填易堵塞且嚴重影響浮選處理量,結(jié)合篩板與填料優(yōu)勢,提出引流介質(zhì)充填旋流-靜態(tài)微泡浮選柱,以解決強旋流與靜態(tài)浮選之間的矛盾.引流介質(zhì)充填在旋流分選和柱浮選之間,在穩(wěn)定靜態(tài)環(huán)境情況下,又引導上移渦旋(負效應)成為平穩(wěn)上升流并促使易浮礦物泡沫快速上浮(正效應),使精選泡沫層更厚、更穩(wěn)定.結(jié)果表明,在原礦品位基本相同情況下,引流介質(zhì)混合充填比篩板充填可以使精礦品位平均提高了1.88%,回收率提高了1.63%.
浮選柱;礦物分選;引流介質(zhì)充填;旋流
旋流-靜態(tài)微泡浮選柱是中國具有自主知識產(chǎn)權的選礦設備[1],目前先后成功應用在鉛鋅尾礦再回收、螢石回收、白鎢分選、銅硫分選、磁鐵礦反浮選等方面,取得了較好的分選指標[2-6].
由充填浮選柱研究知[7-15],大孔隙篩板充填只能部分改善浮選柱渦流狀況和氣泡性能,填料充填會引起嚴重的堵塞問題,且嚴重影響處理量,最終影響浮選效率.
引流介質(zhì)是為了解決強旋流與柱浮選的靜態(tài)化分離之間的矛盾而提出的.它的應用可使上移旋流(負效應)轉(zhuǎn)化為平穩(wěn)上升流(正效應),縮短浮選時間,節(jié)約能耗.筆者主要研究引流介質(zhì)充填對硫化銅礦的浮選影響.
1.1 試驗參數(shù)
1)處理量:20~23 t/d.
2)給礦濃度:45%~49%(質(zhì)量分數(shù)).
3)藥劑(補加粗Ⅱ與掃選部分):黃藥為10~12 g/t;松油為45~55 g/t.
4)液位高度:粗選為0.750~0.820,精選為0.400~0.600.
5)循環(huán)泵工作壓力:粗選為0.18~0.21 MPa,精選為0.17~0.20 MPa.
1.2 原礦礦物組成
中國云南某銅礦.礦物組成如表1所示,礦物以黃銅礦為主,其次是斑銅礦,有微量的銅蘭和孔雀石;鐵礦物以磁鐵礦為主,次為菱鐵礦和黃鐵礦,褐鐵礦微量.大紅山銅礦的脈石礦物以黑云母、長石、白云母、石英及綠泥石為主,其次是方解石、石榴石、高嶺石等.銅礦石為硫化礦,嵌布粒度粗,屬易選礦石.除主要金屬銅、鐵外,還伴生有金、銀、鉑、鈀等稀貴金屬.
表1 礦物組成概量分析表Tab.1 Minerals composition %
1.3 試驗設備和流程
試驗設備聯(lián)系圖見圖1.1對1是指用一臺粗選浮選柱與一臺精選浮選柱進行等體積配置,即粗選容積與精選容積之比為1∶1.浮選柱規(guī)格FCSMC400 mm×4 800 mm.
圖1 1對1配置試驗設備聯(lián)系圖Fig.1 One to one experiment equipment
1.4 引流充填介質(zhì)參數(shù)
篩板參數(shù):圓形;篩孔直徑18 mm,開孔率90%,孔間距2~10 mm;共一層篩板.引流管管徑40 mm,壁厚1.0 mm,高500 mm,開孔率>90%.引流管是PVC材質(zhì)的正六邊形蜂窩狀直管,可任意切割大小和形狀,固定在浮選柱旋流分選上部、柱浮選下部.圖2是引流介質(zhì)模型.
圖2 引流介質(zhì)側(cè)視圖Fig.2 Guiding fluid packed media lateral view
表2是旋流-靜態(tài)微泡浮選柱篩板充填和引流管與篩板混合充填的選別結(jié)果.可以知道,在原礦品位基本相同情況下,混合充填相對于篩板充填,精礦品位平均提高了1.88%,回收率提高了1.63%,分選過程和分選指標都得到顯著改善.
從流態(tài)化角度分析,引流直管實際上就是利用碰撞和阻礙作用對旋流或渦旋進行再整流,當旋流進入直管后,渦旋消失,而上移能量保存,形成上下密度和空隙度均一的流化床層流.
從動力學角度分析也可以知道,小直徑管中雷諾數(shù)會遠小于大直徑浮選柱中雷諾數(shù),微泡與顆粒碰撞概率可能達到最大,“塞流”和逆流碰撞礦化效應得到加強,礦物分選選擇性提高.
表2 篩板充填和混合充填的選別結(jié)果Tab.2 Mixed packing separation and sieved packing separation %
1)引流介質(zhì)充填對浮選柱內(nèi)的流態(tài)和礦化環(huán)境進行了整合,對浮選氣泡進行了剪切,減少氣泡兼并,降低了浮選柱中下部旋流對上部泡沫層的干擾,達到了穩(wěn)定浮選過程、提高浮選效率的目的.
2)引流直管充填形成更小的分選空間,強化傳質(zhì)過程.引流直管強化改變旋流流態(tài)(負效應)為平穩(wěn)上升層流(正效應),使礦化氣泡可以快速浮出,中礦得到強化分選,縮短浮選時間.
3)引流介質(zhì)充填混合充填使旋流-靜態(tài)微泡浮選柱實現(xiàn)了真正意義上的“靜態(tài)化”分離.
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Research of Guiding Fluid Packed Media Enhanced Cyclone-static Flotation Process
ZHANG Min1,2, SHEN Jia-hua1, LIU Dong-yun1
(1.College of Resources and Metallurgy, Guangxi University,Nanning 530004,China; 2.Guangxi Experiment Centre of Science and Technology, Naning 530004,China)
The medium filling can improve the flotation environment effectively. The traditional sieve trays and fillings could only partially inhibit the cyclone flow and usually generate pulp jam. So we put forward the guiding fluid packed media to solve the contradiction of strong cyclonic flow and static separation in the cyclone-static microbubble flotation column. guiding fluid packed media is filled between the cyclone separation and column flotation. while stabling static flotation environment, the upward scroll (negative effect) is guided and become stable upwelling, and the easy floating mineral is rapidly rised (positive effect), and make product concentrate layer more thicker, more stable./ Based on the test data, it was found that the sieve packing has the potential to yield a product of approximately 25.83% copper concentration with 91.78% recovery from a feed concentration of approximately 0.727%. If mixed packing was used, the product concentration could be further increased to 27.60% from a feed of approximately 0.739% concentration with 93.38% recovery.
flotation column; mineral separation;guiding fluid packed media;cyclone flow
2014-09-20;
2014-09-03
國家自然科學基金青年基金資助項目(51404076);廣西教育廳重點課題資助項目(ZD2014005)
張敏(1978-),女,河南永城人,廣西大學副教授,博士,研究方向為浮選柱工藝及其流體動力學,E-mail: scetmin@126.com.
1671-6833(2015)01-0054-03
TS744
A
10.3969/j.issn.1671-6833.2015.01.013