CN102534660A - Method for electrolytically refining crude lead - Google Patents

Abstract

The invention discloses a method for electrolytically refining crude lead. The method comprises the following steps of: adding sodium hydroxide and tartaric acid into water in turn, and stirring to dissolve at normal temperature to obtain a mixed solution; adding lead oxide powder into the mixed solution, dissolving and filtering to obtain filtrate, namely electrolyte; and adding the prepared electrolyte into an electrolytic cell, and switching on direct current for electrolysis by taking a stainless steel plate or a pure lead plate as a cathode and crude lead to be refined as an anode. By the method, smoke and middle slag generated in pyro-refining are avoided, the direct recovery rate of lead and comprehensive recovery rate of valued metals in the refining process are improved, volatile smoke or acid mist cannot be generated, and a defect that electrolyte in a silicofluoric acid system pollutes environment is overcome; meanwhile, the sodium hydroxide and the tartaric acid are added into the electrolyte, so that the sodium hydroxide and the tartaric acid can form a complex with the lead oxide, the concentration of lead ions in the electrolyte is greatly increased and the electrolysis efficiency is improved.

Description

A kind of method of electrorefining lead bullion

Technical field

The present invention relates to plumbous purification refining field, a kind of specifically method of electrorefining lead bullion.

Background technology

For remove in the lead bullion detrimental impurity with reclaim precious metal, must carry out refining to it, the method for the refining of lead bullion is divided two kinds of pyrogenic process and electrolytic process.The master operation of fire refining process is: 1. copper removal: first liquate or condensation copper removal add sulphur degree of depth copper removal again; 2. add caustic soda and remove tellurium; 3. with oxidation style or alkali-chloride improving arsenic removal, antimony, tin; 4. zincification reclaims gold and silver; 5. dezincify; 6. add calcium magnesium and remove bismuth; 7. final refining ingot casting obtains lead bullion.The slag of each operation output is handled respectively to reclaim wherein valuable element.The pyrorefining lead bullion produces quite a large amount of leaded (and other metal) flue dust, various middle slag and sulfur dioxide gas, and contaminate environment is serious, and plumbous simultaneously direct yield and comprehensive recovery are lower.

Compare with pyrogenic process, the waste gas that electrolytic process produces is few, and energy consumption is low, and therefore superior product quality has obtained using widely in the refining of lead bullion.It is Bai Zifa that the extensive method that adopts of lead bullion electrorefining is gone up in industry at present, and promptly lead bullion is cast positive plate, is processed into starting sheet with negative electrode lead, is containing PbSiF ₆With free H ₂SiF ₆Carry out electrolysis in the solution.Bai Zifa is widely used in the plumbous smeltery of states such as China, Canada, Italy, Japan, Peru, Russia at present.But there are some shortcomings in Bai Zifa, like H ₂SiF ₆Volatile, the job site can produce a large amount of acid mists, and the smell is awful, PbSiF ₆The preparation process in can emit HF and SiF ₄Gas, to human body and environmental hazard very big (volume such as Beijing Nonferrous Metallurgy Design Research Institute, the heavy non-ferrous metal smelting DM: plumbous zinc bismuth volume, Beijing: metallurgical industry press, 1995, P88-106, P119-146).Other acid system of once studying has muriate, nitrate salt, borate salt system etc., but only limits to plumbous electrodeposition, do not see the report that is applied to the refining of lead bullion as yet, and acid electrolyte is volatile, pollutes generally bigger.

Summary of the invention

The present invention for solve prior art when the lead bullion electrorefining to environment and the very big problem of human harm; A kind of method of electrorefining lead bullion is provided; This method is through carrying out the electrorefining of lead bullion in containing tartaric basic soln, can alleviate the environmental pollution of electrolytic process and to the harm of human body.

The present invention solves the problems of the technologies described above the technical scheme of employing to be: a kind of method of electrorefining lead bullion; Add sodium hydroxide, tartrate in the entry successively; Stirring and dissolving makes mixing solutions at normal temperatures, and the add-on of tartrate and sodium hydroxide is to add 100 ~ 160g tartrate, 80 ~ 160g sodium hydroxide in every liter of mixing solutions; In mixing solutions, adding lead oxide powder then, is stirring and dissolving under 40 ~ 98 ℃, the condition of stirring velocity 200 ~ 400r/min in temperature, and time 1 ~ 6h filters then, and gained filtrating is electrolytic solution; The granularity of described lead oxide powder is less than 200 orders, and plumbum ion concentration is 80 ~ 130g/L in the electrolytic solution for preparing;

The electrolytic solution that makes is added in the electrolyzer; Adopt stainless steel plate or pure stereotype as negative electrode, adopt and treat that the purified lead bullion processes anode, feed direct current and carry out electrolysis; Concrete electrolytic process parameter is: 40 ~ 60 ℃ of electrolyte temperatures; The circulation of elecrolyte cycle is 45 ~ 120min, the circulation of elecrolyte mode under go out cathode current density 100 ~ 160A/m on advancing ², bath voltage 0.25 ~ 1.0V, anodic current density 100 ~ 160A/m ², with interpole gap 80 ~ 130mm;

Rise to 1.0V when bath voltage in the electrolytic process, when promptly anode passivation taking place, take out positive plate and scrub or the double teeming positive plate, scrub or double teeming after positive plate return the participation electrolysis;

According to the steam output of electrolytic solution, timing make up water in electrolytic solution is to keep plumbum ion concentration 80 ~ 130g/L in the electrolytic solution, sodium hydroxide 80 ~ 160 g/L and tartaric acid concentration 100 ~ 160 g/L;

The dirt settling of collecting on the negative electrode is the lead that obtains after the refining.

Among the present invention, said tartrate, sodium hydroxide and plumbous oxide are analytical pure or technical grade reagent.

The present invention can carry out when scrubbing anode during dirt settling on collecting negative electrode.

Among the present invention; Adding sodium hydroxide and tartaric reason are when preparing electrolyte: sodium hydroxide and tartrate can form a kind of structure that is similar to title complex with plumbous oxide; Can increase the concentration of lead ion in the electrolytic solution greatly; The electrolytic solution of alkalescence is also more stable when electrolysis simultaneously, can not produce the gas to environment and human body harmful.

Among the present invention, in electrolytic process, by the anode of lead bullion cast, under the effect of electric current, lead constantly enters into electrolytic solution and forms title complex, and title complex obtains electron reduction for plumbous at negative electrode then; Anode constantly dissolves, and final anode is remaining to be the anode sludge that anode scrap and precious metal are formed.

The present invention is applicable to the lead bullion of plumbous smelting process output, and its staple scope is: Pb 96% ~ 99%, Sb 0.5% ~ 3%, and Cu 0.05% ~ 3%, and As 0.005% ~ 1.5%, and Sn 0.02% ~ 1%, and Bi 0.1% ~ 1%, and Ag 0.1% ~ 3%; Also be suitable for handling lead antimony alloy, lead bismuth alloy etc.

Beneficial effect: the present invention and traditional plumbous refinery practice compare, and following advantage is arranged: 1, the present invention has avoided various flue dust, the middle slag that pyrorefining produces, and has improved the direct yield of refining process lead and the comprehensive recovery of various valuable metals;

2, the alkaline organic electrolysis system is environmentally friendly, can not produce volatilization flue dust or acid mist, has overcome the shortcoming of silicofluoric acid system electrolyte contamination environment;

3, adding sodium hydroxide and tartrate can form title complex with plumbous oxide in the electrolytic solution, have increased the concentration of lead ion in the electrolytic solution greatly, have improved electrolytic efficiency.

Embodiment

Below in conjunction with specific embodiment the present invention is done further elaboration.

Embodiment 1

Lead content in the lead bullion is 98.30%, and the major impurity composition is tin 0.0008%, antimony 0.8281%, bismuth 0.1363%, arsenic 0.5127%, copper 0.0795%, zinc 0.0006%, silver 0.1406%, iron 0.0013%.Tartrate, sodium hydroxide and plumbous oxide are analytical pure.

Take by weighing lead bullion 500 g, 600 ℃ of fusing 15 min that heat take out in retort furnace, in graphite jig, are cast into positive plate, are of a size of 10cm * 10cm.

Take by weighing 200 g plumbous oxide, 180 g sodium hydroxide, 180 g tartrate add in the 1.5 L water, and 70 ℃ of magnetic agitation 4 h filter, and promptly obtain electrolytic solution, and wherein plumbum ion concentration is 110g/L.55 ℃ of control electrolysis temperatures, current density 140 A/m ², pole span 4 cm, pole plate area 9.7 cm * 9.9 cm, circulation of elecrolyte speed 30 mL/min when bath voltage is increased to 1.0V, take out positive plate, scrub to put into electrolyzer behind the anode sludge and continue electrolysis, and electrolysis time amounts to 24h.Average cell voltage 0.32V, current efficiency 98.93%, negative electrode energy consumption 83.69 kWh/t Pb.The constituent content of the negative electrode lead and the anode sludge is seen table 1 and table 2 respectively.

The foreign matter content (* 10 that table 1 negative electrode is plumbous ^-6%)

Element	Sn	Sb	Bi	As	Cu	Zn	Fe	Ag	Ni	Cd	Summation
												Negative electrode is plumbous	＜8.9	＜8.9	2880	15.8	573	＜8.9	310	＜8.9	＜8.9	＜8.9	＜3832.2
GB (<=)	500	800	4000	500	1000	400	500	800	-	-	6000

The constituent content of table 2 anode sludge (%)

Element	Sn	Sb	Bi	As	Cu	Zn	Fe	Ag	Ni	Cd
											The anode sludge	-	12.28	10.84	33.83	7.188	-	0.464	10.66	0.109	-

Can be found out that by table 1 foreign matter content in the negative electrode lead is very low, the purity of negative electrode lead is higher, is higher than 99.99617%, has reached the standard of Pb99.994 lead pig among the GB/T 469-2005.Can find out that by table 2 enrichment of element such as silver, bismuth, antimony are in the anode sludge.

Embodiment 2

The content of the lead in the lead bullion is 98.10%, and the major impurity composition is tin 0.0008%, antimony 0.9106%, bismuth 0.1959%, arsenic 0.5451%, copper 0.0933%, zinc 0.0006%, silver 0.1521%, iron 0.0015%.Tartrate, sodium hydroxide and plumbous oxide are analytical pure.

Take by weighing lead bullion 500g, in retort furnace, heat, take out, in graphite jig, be cast into positive plate, be of a size of 10cm * 10cm to 650 ℃ of fusing 15min.

Get 180 g plumbous oxide, 210 g sodium hydroxide, 210 g tartrate add in the 1.5 L zero(ppm) water, and 80 ℃ of magnetic agitation 4 h promptly obtain electrolytic solution after the filtration, and wherein plumbum ion concentration is 100g/L.45 ℃ of control electrolysis temperatures, current density 160 A/m2, pole span 4 cm, pole plate area 9.7 cm * 9.9 cm, electrolytic solution volume 1.5 L, circulation of elecrolyte speed 30 mL/min.When bath voltage is increased to 1.0V, take out positive plate, scrub and put into electrolyzer behind the anode sludge and continue electrolysis, electrolysis time amounts to 25h.Average cell voltage 0.39V, current efficiency 98.77%, negative electrode energy consumption 102.16 kWh/t Pb.Negative electrode the constituent content plumbous and anode sludge is seen table 3 and table 4 respectively.

The foreign matter content (* 10 that table 3 negative electrode is plumbous ^-6%)

Element	Sn	Sb	Bi	As	Cu	Zn	Fe	Ag	Ni	Cd	Summation
												Negative electrode is plumbous	＜9.5	＜9.5	3100	19.8	540	＜9.5	335	＜9.5	＜9.5	＜9.5	＜4042.3
GB (<=)	500	800	4000	500	1000	400	500	800	-	-	6000

The constituent content of table 4 anode sludge (%)

Element	Sn	Sb	Bi	As	Cu	Zn	Fe	Ag	Ni	Cd
											The anode sludge	-	14.58	9.431	31.53	6.673	-	0.312	9.85	0.0845	-

Can find out that by table 3 the plumbous purity of negative electrode is 99.99596%, has reached the standard of Pb99.994 lead pig among the GB/T 469-2005.Can find out that by 4 enrichment of element such as silver, bismuth, antimony are in the anode sludge.

Embodiment 3

Lead content in the lead bullion is 98.30%, and the major impurity composition is tin 0.0008%, antimony 0.8281%, bismuth 0.1363%, arsenic 0.5127%, copper 0.0795%, zinc 0.0006%, silver 0.1406%, iron 0.0013%.Tartrate, sodium hydroxide and plumbous oxide are analytical pure.

Take by weighing lead bullion 500 g, 600 ℃ of fusing 15 min that heat take out in retort furnace, in graphite jig, are cast into positive plate, are of a size of 10cm * 10cm.

Take by weighing 100 g plumbous oxide, 120g sodium hydroxide, 150 g tartrate add in the 1.5 L water, and 70 ℃ of magnetic agitation 4 h filter, and promptly obtain electrolytic solution, and wherein plumbum ion concentration is 80g/L.40 ℃ of control electrolysis temperatures, current density 100 A/m ², pole span 4 cm, pole plate area 9.7 cm * 9.9 cm, circulation of elecrolyte speed 8.5 mL/min when bath voltage is increased to 1.0V, take out positive plate, scrub to put into electrolyzer behind the anode sludge and continue electrolysis, and electrolysis time amounts to 24h.Average cell voltage 0.27V, current efficiency 99.15%, negative electrode energy consumption 70.45 kWh/t Pb.The constituent content of the negative electrode lead and the anode sludge is seen table 5 and table 6 respectively.

The foreign matter content (* 10 that table 5 negative electrode is plumbous ^-6%)

Element	Sn	Sb	Bi	As	Cu	Zn	Fe	Ag	Ni	Cd	Summation
												Negative electrode is plumbous	＜8.9	＜8.9	1850	12.6	435	＜8.9	230	＜8.9	＜8.9	＜8.9	＜2581
GB (<=)	500	800	4000	500	1000	400	500	800	-	-	6000

The constituent content of table 6 anode sludge (%)

Element	Sn	Sb	Bi	As	Cu	Zn	Fe	Ag	Ni	Cd
											The anode sludge	-	13.44	10.97	35.27	8.322	-	0.489	10.83	0.112	-

Can be found out that by table 5 foreign matter content in the negative electrode lead is very low, the purity of negative electrode lead is higher, is higher than 99.99741%, has reached the standard of Pb99.994 lead pig among the GB/T 469-2005.Can find out that by table 6 enrichment of element such as silver, bismuth, antimony are in the anode sludge.

Embodiment 4

Lead content in the lead bullion is 98.30%, and the major impurity composition is tin 0.0008%, antimony 0.8281%, bismuth 0.1363%, arsenic 0.5127%, copper 0.0795%, zinc 0.0006%, silver 0.1406%, iron 0.0013%.Tartrate, sodium hydroxide and plumbous oxide are analytical pure.

Take by weighing lead bullion 500 g, 600 ℃ of fusing 15 min that heat take out in retort furnace, in graphite jig, are cast into positive plate, are of a size of 10cm * 10cm.

Take by weighing 250 g plumbous oxide, 240 g sodium hydroxide, 240 g tartrate add in the 1.5 L water, and 70 ℃ of magnetic agitation 4 h filter, and promptly obtain electrolytic solution, and wherein plumbum ion concentration is 130g/L.55 ℃ of control electrolysis temperatures, current density 160 A/m ², pole span 4 cm, pole plate area 9.7 cm * 9.9 cm, circulation of elecrolyte speed 30 mL/min when bath voltage is increased to 1.0V, take out positive plate, scrub to put into electrolyzer behind the anode sludge and continue electrolysis, and electrolysis time amounts to 24h.Average cell voltage 0.38V, current efficiency 98.27%, negative electrode energy consumption 100.05 kWh/t Pb.The constituent content of the negative electrode lead and the anode sludge is seen table 7 and table 8 respectively.

The foreign matter content (* 10 that table 7 negative electrode is plumbous ^-6%)

Element	Sn	Sb	Bi	As	Cu	Zn	Fe	Ag	Ni	Cd	Summation
												Negative electrode is plumbous	＜8.9	＜8.9	3250	17.4	698	＜8.9	421	＜8.9	＜8.9	＜8.9	＜4749.8
GB (<=)	500	800	4000	500	1000	400	500	800	-	-	6000

The constituent content of table 8 anode sludge (%)

Element	Sn	Sb	Bi	As	Cu	Zn	Fe	Ag	Ni	Cd
											The anode sludge	-	11.13	10.62	31.53	6.205	-	0.375	10.35	0.115	-

Can be found out that by table 7 foreign matter content in the negative electrode lead is very low, the purity of negative electrode lead is higher, is higher than 99.99525%, has reached the standard of Pb99.994 lead pig among the GB/T 469-2005.Can find out that by table 8 enrichment of element such as silver, bismuth, antimony are in the anode sludge.

Claims (1)

1. the method for an electrorefining lead bullion; It is characterized by: add sodium hydroxide, tartrate in the entry successively; Stirring and dissolving makes mixing solutions at normal temperatures, and the add-on of tartrate and sodium hydroxide is to add 100 ~ 160g tartrate, 80 ~ 160g sodium hydroxide in every liter of mixing solutions; In mixing solutions, adding lead oxide powder then, is stirring and dissolving under 40 ~ 98 ℃, the condition of stirring velocity 200 ~ 400r/min in temperature, and time 1 ~ 6h filters then, and gained filtrating is electrolytic solution; The granularity of described lead oxide powder is less than 200 orders, and plumbum ion concentration is 80 ~ 130g/L in the electrolytic solution for preparing;

The electrolytic solution that makes is added in the electrolyzer; Adopt stainless steel plate or pure stereotype as negative electrode, adopt and treat that the purified lead bullion processes anode, feed direct current and carry out electrolysis; Concrete electrolytic process parameter is: 40 ~ 60 ℃ of electrolyte temperatures; The circulation of elecrolyte cycle is 45 ~ 120min, the circulation of elecrolyte mode under go out cathode current density 100 ~ 160A/m on advancing ², bath voltage 0.25 ~ 1.0V, anodic current density 100 ~ 160A/m ², with interpole gap 80 ~ 130mm;

Rise to 1.0V when bath voltage in the electrolytic process, when promptly anode passivation taking place, take out positive plate and scrub or the double teeming positive plate, scrub or double teeming after positive plate return the participation electrolysis;

According to the steam output of electrolytic solution, timing make up water in electrolytic solution is to keep plumbum ion concentration 80 ~ 130g/L in the electrolytic solution, sodium hydroxide 80 ~ 160 g/L and tartaric acid concentration 100 ~ 160 g/L;

The dirt settling of collecting on the negative electrode is the lead that obtains after the refining.