A kind of method of utilizing low-grade zinc oxide ore to produce high-purity nm zinc oxide
Technical field
The present invention relates to a kind of production method of zinc oxide, particularly a kind of production method of high-purity nano zinc oxide.
Background technology
The production of zinc oxide product is at present generally carried out roasting with the high ore deposit of zinc content and is become zinc baking sand to make raw material, and rate is higher because it contains zinc, and lixiviate is relatively easy.Along with exploitation all the year round, the higher-grade mineral resources is fewer and feweri, and grade also reduces gradually, and people are existing, and oneself starts to note the utilization of zinc oxide ore.Lower (valuable element content Zn is below 30% but zinc oxide ore contains the zinc rate usually; Pb 0.15%; Cu 0.008%; Mn 0.06%), and complicated component, exist mainly with smithsonite, franklinite and lapis calaminaris, high (the about Fe respectively of gangue content ferric oxide in ore, silicon oxide, calcium oxide, content of magnesia
2O
34-7%; SiO
23-5%; CaO30-32%; MgO 7-8%), silt content is also heavy.Comprehensive reutilization is worth little, and all more difficult to ore dressing, the acidleach of zinc, beneficiation cost is high, is the long-standing great technical barrier of domestic and international ore dressing.Recent domestic is with the solution of zinc sulfate that contains strong acid, zinc oxide ore to be leached, although zinc leaching rate increases mostly to the method for the lixiviate of zinc oxide ore, but the iron, the silicon amount that enter solution are also high, the deironing difficulty, the consumption amount of reagent is large, and it is many that washings is taken away zinc.China's publication such as CN1477217 A improve aforesaid method, first adopt the solution of sulfur acid zinc pH=3-4 to carry out the neutrality leaching, then hang down Ore Leaching technique.But franklinite, lapis calaminaris decompose slowly in low sour situation, the problems such as leaching efficiency is low, cost is high, environmental pollution still exist.Many metallargists both domestic and external think, zinc content should not be processed by wet-leaching technique separately lower than 20% zinc oxide ore.
Optimal method is that the selectivity of carrying out zinc leaches, and zinc is entered in solution, and zinc obtains valuable recycling.
On the other hand, the quality percentage composition that high-purity zinc oxide generally refers to zinc oxide is 99.7% and above zinc oxide product, high-purity zinc oxide is the indispensable a kind of high-tech raw material of modern industry, of many uses, be mainly used in the tens of kinds of industry and enterprises such as glass, feed, pottery, dyestuff, paint, papermaking, rubber, agricultural chemicals, oil refining, zinc-plated, special steel material, alloy, science and techniques of defence, no matter be glass, papermaking, or rubber, oil refining etc. all are in great demand to zinc oxide, and purity requirement is very high.
Nano zine oxide (ZnO) be a kind of particle diameter between 1-100 nm, novel high function fine inorganic product geared to the 21st century, show much special character, as non-migrating, fluorescence, piezoelectricity, absorption and scatters ultraviolet ability etc., utilize its marvellous performance at aspects such as light, electricity, magnetic, sensitivities, can manufacture gas sensor, fluor, varistor, UV-preventing material, image recording material, piezoelectric, voltage dependent resistor, effective catalyst, magneticsubstance and plastics film etc.
Produce at present the method for nano zine oxide, mainly contain chemical precipitation method, sol-gel method, microemulsion method and hydrothermal synthesis method etc.But the raw material adopted is all that zinc content is at the zinc baking sand more than 50% or pure zinc salt (as zinc sulfate, zinc nitrate, zinc acetate) etc.
Ammonia process is a kind of common method for preparing zinc oxide, the general step of ammonia process (ammonia-volatile salt associating lixiviation process is produced zinc oxide) comprising at present: ammonia-carbon ammonium is that leaching agent leaches and makes leaching liquid material containing zinc, and leaching liquid makes zinc oxide product through purification, ammonia still process crystallization, drying and calcining.
This traditional ammonia process prepares the processing that zinc oxide never is applied to low-grade zinc oxide ore, and major cause is:
1. because of mineral, contain the zinc rate low, silt content is high, and it is low that leach liquor contains zinc concentration, and the leaching agent consumption is large, and cost is high, and enterprise can't bear.
2. because of the impurity component complexity, the conforming product rate of production is low, and product price is hanged down deficiency in economic performance.
3. when conventional means leached, the leaching yield of zinc ore was low, and the high waste of the remaining zinc of leached mud is large, and the value of zinc ore is not used and embodies.
Current published method for producing nanometer-zinc oxide by ammonia leaching technology, such as:
Chinese patent application numbers 92103230.7 has been announced a kind of improvement technology for the legal production zinc oxide of traditional ammino, by the zinc ammonia complex liquid thin up after purifying, make the hydrolysis of part zinc ammonia complex liquid, obtain zinc subcarbonate, then continue heating until the decomposition of zinc ammonia complex liquid is complete, the zinc subcarbonate obtained makes the nano zine oxide of 30-100nn through high-temperature calcination.
The following problem of this technical patent needs to solve:
After hydrolysis, undecomposed zinc ammonia complex liquid is in the thermal degradation process, and the new zinc subcarbonate produced can, in original xln surface growth, impel the crystal of former hydrolysis to grow up, easily cause zinc subcarbonate xln particle diameter inhomogeneous, make the finished product particle diameter wayward.
Chinese patent application numbers 200610130477.7 discloses a kind of improvement technology for the legal production zinc oxide of traditional ammino, by zinc ammonia complex liquid, with the hot water of 1:2-20 or the mother liquor of heat, mix continuously, mother liquor is cycled to used in the hydrolysis that the zinc ammino closes liquid after heating, make the nano zine oxide of 10-50nn.
The following problem of this technical patent needs to solve:
In mother liquor, ammonia can not be separated fully, does not reach the effect of hydrolysis crystallization zinc subcarbonate, totally gets back to again the time that Traditional Method need to be grown if ammonia separates, and causes the thick zinc subcarbonate crystallization of precipitate particle.
Above two kinds of patents are in fact all to manage at low temperatures, utilize the Macrodilution of water to make the pH value of solution slight the change occur and hydrolysis crystallization acquisition part Nanocrystal, only actually relies on the slight change of pH value can only obtain few part hydrolysis (can find from zinc oxide) in situation when zinc concentration is higher ammonia solvent is write music line chart.The efficiency separated out of the zinc ammoniacal liquor of high density is high in fact, energy consumption is low, and the efficiency that the zinc ammoniacal liquor of lower concentration is separated out is low, energy consumption is high, the people be the proportional that adds flood can to obtain nano oxidized zinc product be feasible technically, but may not be feasible aspect economic benefit.
In sum, for the processing of low-grade zinc oxide ore, how in low levels zinc material, effectively to leach zinc wherein, and obtain having concurrently high-purity and nano level zinc oxide, overcome simultaneously traditional pyrogenic process and the shortcoming of wet method, become industry technical barrier urgently to be resolved hurrily.
Summary of the invention
Goal of the invention of the present invention is: for the problem of above-mentioned existence, the zinc in a kind of efficient recovery low-grade zinc oxide ore is provided and prepares the method for high-purity nm zinc oxide.
The technical solution used in the present invention is such: a kind of method of utilizing low-grade zinc oxide ore to produce high-purity nm zinc oxide comprises the following steps:
The leaching low-grade zinc oxide ore makes leaching liquid, leaching liquid through pre-ammonia still process, purification and impurity removal, refinement treatment, ammonia still process crystallization and drying and calcining, wherein,
While leaching pending low-grade zinc oxide ore, leach as leaching agent with ammoniacal liquor-ammonium fluid; Wherein ammonia, gas concentration lwevel are respectively c (NH
3)=5.5-7mol/L, c (CO
3 2-)=0.95-1.5 mol/L, and in the leaching agent of every cubic metre, add the 0.3-0.5kg Sodium Silicofluoride, after leaching, obtain leaching liquid;
Before the purification and impurity removal step, carry out pre-ammonia still process: leaching liquid is heated to 90-95 ℃, removes the part free ammonia, until solution ammonia concentration c (NH
3During)=3.0-3.5mol/L, then add the ratio of 2-3kg to add the ammonium persulphate oxidation in every cubic metre of leaching liquid, carry out solid-liquid separation after iron, manganese oxidation fully, solution enters the purification and impurity removal step;
After purification and impurity removal, carry out refinement treatment, method is: the solution after purification and impurity removal is processed adds ammonium phosphate and tensio-active agent, and add-on is to add 0.5-1.0kg ammonium phosphate, 30-50g tensio-active agent in the liquid after every cubic metre of purification and impurity removal is processed;
Purification and impurity removal, ammonia still process crystallization and drying and calcining step all adopt current common ammonia process to prepare the processing parameter of zinc oxide.
Obtain high-purity zinc oxide, at first need to guarantee that the zinc in low-grade zinc oxide ore can leach as much as possible, can improve the rate of recovery of zinc so on the one hand, on the other hand, the content of zinc is larger in leach liquor, foreign matter content is also just less, and guarantee makes more high-purity zinc oxide under equal processing condition.Namely for the recycling of low-grade zinc oxide ore, zinc " soaks and draws " and " removes totally " with impurity, is the technical problem of most critical.
In order to solve the problems of the technologies described above, the technology that at first the present invention prepares existing ammonia process zinc oxide is applied to the processing to low-grade zinc oxide ore, simultaneously, on the technique basis of existing ammonia process, in leaching liquid, add appropriate Sodium Silicofluoride, to solve the problem of " soak and draw "; And, before purification and impurity removal, increased the step of pre-ammonia still process, to solve the problem of " removing totally ".
Because the gangue content oxidation content of calcium and magnesium of low-grade zinc oxide ore is high, can not leach with acid system, not only acid consumes greatly, also makes a large amount of calcium, magnesium stripping, purifies difficulty.So the present invention adopts ammonia process to leach, ultrafine particulate in the mineral gangue also plays certain deadening effect to leaching agent, in order to address this problem, the present inventor draws by great many of experiments: appropriate silicofluoric acid is received and can be abolished ultrafine particulate to containing zinc particle package action, realize ultrafine particulate layering floating, thereby zinc is exposed, it more fully is immersed in leach liquor.
Simultaneously, the present inventor draws by great many of experiments: before purification and impurity removal, increase pre-ammonia still process step, reduce on the one hand the free ammonia in solution, lower the complexing coefficient of foreign ion, be beneficial to the raising depuration quality, reduce and purify drug dosage.
Secondly, obtain nano level zinc oxide, need to be in corresponding steps, growing up of inhibited oxidation zinc crystal grain, the nano zine oxide that prior art obtains why size and particle size distribution range can not be fully up to expectations, most important reason is constantly the growing up of crystal in treating processes, namely can produce agglomeration, especially for the raw material of this low zinc content of low-grade zinc oxide ore, processes.In order to address the above problem, the present inventor, by great many of experiments, after purification and impurity removal, increases the step of refinement treatment, in the liquid after purification and impurity removal is processed, adds appropriate ammonium phosphate and tensio-active agent, effectively the growth of inhibited oxidation zinc particle.
Wherein:
The chemical equation of leaching step is:
ZnO+nNH
3 +H
2O→[Zn(NH
3)n]
2++2OH
-
ZnFe
2O
4 +nNH
3+4H
2O→[Zn(NH
3)n]
2++2Fe(OH)
3 ↓+2OH
-
ZnFe
2O
4 +nNH
3+H
2O→[Zn(NH
3)n]
2++Fe
2O
3↓+2OH
-
Zn
2SiO
4 +2nNH
3→ 2[Zn(NH
3)n]
2+ + SiO
4 4-
Zn(OH)
2 +nNH
3 →[Zn(NH
3)n]
2++2OH
-
ZnCO
3+nNH
3→[Zn(NH
3)n]
2++CO
3 2-
N=1~4 wherein;
Utilize the pyrosol of pre-ammonia still process, add ammonium persulphate to stir and carry out oxidation, as Fe
3+, AsO
3 3-, Mn
2+Produce co-precipitation, reduced follow-up purification difficulty, reduced the reagent consumption amount, provide cost savings reaction equation:
5(NH
4)
2S
2O
8 +2Mn
2++8H
2O →2NH
4MnO
4+4(NH
4)
2SO
4 +16H
++ 6SO
4 2-
S
2O
8 2-+Mn
2++2NH
3·H
2O+H
2O→MnO(OH)
2↓ +2NH
4 2++2SO
4 2-+2H
+
S
2O
8 2-+2Fe
2+ +6NH
3·H
2O →2SO
4 2-+ 2Fe(OH)
3↓+6NH
4 +
As
2O
3+3H
2O→2H
3AsO
3
2H
3AsO
3+8Fe(OH)
3→(Fe
2O
3)
4As
2O
3·5H
2O↓+10H
2O
AsO
4 3-+Fe
3-→FeAsO
4↓
Ca
2++HCO
3 -+2OH
-→ CaCO
3↓+H
2O ;
Zinc ammonia complex liquid after the oxidation of abovementioned steps ammonium persulphate, separation is again through sodium persulfide precipitation of heavy metals impurity, then through separation impurity such as potassium permanganate secondary oxidation iron, manganese, purification obtains the zinc ammino and closes refined liquid through the zinc powder drastic reduction again; Reaction equation:
M
2++ S
2→ MS ↓ M represents Cu
2+, Pb
2+, Cd
2+, Ni
2+Hg
2+Plasma
As
3+ + S
2-→As
2S
3↓
3Fe
2+ + MnO
4 - + 7H
2O → MnO
2 ↓+ 3Fe(OH)
3↓ + 5H
+
3Mn
2+ + 2MnO
4 - +2H
2O → 5MnO
2↓ +4H
+
Y
2++ Zn → Zn
2+Wherein Y representative of+Y: Cu
2+, Pb
2+, Cd
2+, Ni
2+Plasma
The refinement treatment chemical equation:
3[Zn(NH
3)n]
2++2(NH
4)
3PO
4+6OH
-→[Zn(NH
3)n]
3(PO
4)
2 + 6NH
3·H
2O
The reaction equation of ammonia still process step:
3[Zn(NH
3)
4]CO
3 + H
2O →ZnCO
3·2Zn(OH)
2·H
2O ↓ + 12NH
3↑ + 2CO
2↑
The chemical equation of drying and calcining:
ZnCO
3·2Zn(OH)
2·H
2O→ 3ZnO +3H
2O↑ +CO
2
As preferably: while leaching pending low-grade zinc oxide ore, in the ammoniacal liquor-ammonium fluid of every cubic metre, also be added with the Dicyanodiamide of 0.5-1kg and the tensio-active agent of 0.03-0.05kg.
The surface energy of decreasing by surfactant solution, with the Sodium Silicofluoride mating reaction, increase soaking and permeating, dissolving and the leaching of promotion zinc the zinc particle.
As preferably: the Dicyanodiamide that also is added with 0.5-1kg in the ammoniacal liquor-ammonium fluid of every cubic metre.
Dicyanodiamide, as the ammonia stablizer, can reduce the volatilization of ammonia in leaching process, improves the leaching Working environment, reduces the loss of ammonia.
As preferably: adopt wet ball grinding to leach during the low-grade zinc oxide ore leaching.
As preferably: guarantee that in ball mill, extraction time is 50~60 minutes, the ball mill outlet material is all by 140 mesh sieves, i.e. particle diameter≤109 μ m.
Utilize the ball milling wet extraction, destroyed ore crystalline network (mechanical activation) and combined with the Surfactant Chemistry activation, reach higher leaching velocity and leaching yield
As preferably: in the ammonia still process crystallisation process, detect at any time liquid zinc content in ammonia still, when the mass content of zinc during at 1-1.5%, in ammonia still process equipment, add sodium hydroxide solution, the sodium hydroxide solution added is that to add the quality percentage composition be 30% sodium hydroxide solution 3-5 liter to every cubic metre of ammonia still process liquid, zinc quality percentage composition lower than 0.3% the time, finishes ammonia still process.
In the ammonia still process process, when ammonia concentration in zinc ammonia complex liquid is low, by increasing sodium hydroxid, improve the pH value of liquid, make NH
4 +Transfer free NH to
3Molecule reaches quick deamination, the purpose of rapid crystallization.Crystallization velocity is faster, and the chance of impurity parcel crystal is just less, thereby improves the purity of crystal.
In sum, owing to having adopted technique scheme, the invention has the beneficial effects as follows: ammonia process is applied to the processing to the electrolysis low-grade zinc oxide ore, and existing ammonia process has been carried out to adaptation, when leaching, add Sodium Silicofluoride, tensio-active agent and Dicyanodiamide, make the zinc of low-grade zinc oxide ore quick on the one hand, as far as possible fully leach, make the zinc in low-grade zinc oxide ore be fully recycled, after leaching, increased simultaneously pre-ammonia still process step, remove unnecessary free ammonia and utilize purification and impurity removal, for making high-purity high-quality zinc oxide, lay a good foundation, by the processing of the technology of the present invention means, the zinc oxide purity obtained through 350-450 ℃ of calcining can reach more than 99.7%, and particle diameter is at the nano oxidized zinc product of 10-50nm.Has very high economic worth; In addition, treatment process energy consumption of the present invention is low, efficiency is high, the leaching agent recycle.Through soaking slag the end of leaching processing, do not destroy original mineral composition structure, still can brickmaking etc. have reached economic environmental protection dual purpose.
Embodiment
Below the present invention is described in detail.
In order to make purpose of the present invention, technical scheme and advantage clearer, below in conjunction with embodiment, the present invention is further elaborated.Should be appreciated that specific embodiment described herein, only in order to explain the present invention, is not intended to limit the present invention.
Embodiment 1
Raw material: Yunnan zinc oxide ore 1
#, its composition is: Zn15.48%. Fe18. 20%. Si027. 94%, its zinc phase composition are zinc carbonate 9.49%, zinc silicate 2. 12%. zinc sulphide 0. 7 3%, automolite 3.14 %.
Method for the preparation of high-purity zinc oxide:
(1) leaching: get 500g oxidized ore 1
#, leach as leaching agent with 1500ml ammoniacal liquor-ammonium fluid; Wherein, NH in described leaching agent
3Volumetric molar concentration c (NH
3)=5.5mol/L, CO
3 2-Volumetric molar concentration c (CO
3 2-)=1.2 mol/L, add Sodium Silicofluoride by the amount of adding the 0.3kg Sodium Silicofluoride in every cubic metre of leaching agent in leaching agent; Adding up to leaching time is 3 hours, and temperature is 25-40 ℃; After solid-liquid separation, zinc 68.5 grams in gained zinc ammonia complex liquid; The leaching yield of zinc oxide ore zinc is 88.5%;
(2) pre-ammonia still process: leaching liquid is heated to 90 ℃, remove the part free ammonia, steam while to ammonia concentration in liquid, being 3.5mol/L, then add the ratio of 2kg to add ammonium persulphate in every cubic metre of leaching liquid, liquid after pre-ammonia still process is carried out to solid-liquid separation, and solution enters the purification and impurity removal step;
(3) purification and impurity removal: add 2.1g potassium permanganate to stir 0.5h in the liquid after pre-ammonia still process, add a small amount of polyacrylamide solution (4mg/L) to filter, filtrate adds sodium sulphite by 1.2 times of the theoretical amount of precipitate C u, Cd, the required sodium sulphite of Pb, temperature, 70 ℃, churning time 2h, filter, and filtrate adds KMnO
4Consumption is 2.7 times of Fe amount, and 80 ℃ of temperature stir 1h (detecting Fe, Mn qualified), filter, and filtrate adds zinc powder by 2.5 times that replace Cu, Cd, the required theoretical zinc powder of Pb, stirs 30min, and temperature 60 C filters;
(4) refinement treatment, method is: in the liquid after purification and impurity removal is processed, add ammonium phosphate and tensio-active agent, add-on is to add 1kg ammonium phosphate, 50g surfactant SDS in the liquid after every cubic metre of purification and impurity removal is processed, and obtains refined liquid;
(5) ammonia still process crystallization: the gained refined liquid is inserted in ammonia distiller and carried out ammonia still process, vapour pressure import 0.5MPa/cm
2, 105 ℃ of solution temperatures, until [ Zn
2+During ]=1.5g/L, stop ammonia still process, the emulsion obtained carries out solid-liquid separation, and filter cake is by the washing of liquid-solid ratio 5:1 clear water, and washing time 1h, refilter separation, obtains filter cake;
(6) drying and calcining: 105 ℃ of dryings of filter cake, obtain powder, through 450 ℃ of retort furnace calcining 60min, sampling detects and obtains purity ZnO%=99.73%; Median size 13.5nm (XRD live width method), specific surface area 90m
2The high-purity zinc oxide powder of/g.
Embodiment 2
Raw material: oxidized ore 2
#, its composition is: Zn9.67%. Fe19.33%. Si026. 63%, its zinc phase composition of CaO28.34% are zinc carbonate 12.28%, zinc silicate 2. 37%. zinc sulphide 0. 8 2%, automolite 3. 20%.
Method for the preparation of high-purity zinc oxide:
(1) leaching: get 500g oxidized ore 1
#, leach as leaching agent with 1500ml ammoniacal liquor-ammonium fluid; Wherein, NH in described leaching agent
3Volumetric molar concentration c (NH
3)=7mol/L, CO
3 2-Volumetric molar concentration c (CO
3 2-)=0.95 mol/L, add Sodium Silicofluoride by the amount of adding the 0.5kg Sodium Silicofluoride in every cubic metre of leaching agent in leaching agent; Amount by the Dicyanodiamide of the surfactant SDS of adding 0.4kg Sodium Silicofluoride, 0.03kg in every cubic metre of leaching agent, 1kg adds respectively Sodium Silicofluoride, SDS and Dicyanodiamide respectively; When leaching, adopt ball milling, and guarantee that in ball mill, extraction time is 60 minutes, the ball mill outlet material is all by 140 mesh sieves, and adding up to leaching time is 3 hours, and temperature is 25-40 ℃; Zinc 42.7 grams in gained zinc ammonia complex liquid; The leaching yield 88.3% of zinc oxide ore zinc;
(2) carry out pre-ammonia still process: leaching liquid is heated to 95 ℃, remove the part free ammonia, steam while to ammonia concentration in liquid, being 3.0mol/L, then add the ratio of 3kg to add ammonium persulphate in every cubic metre of leaching liquid, liquid after pre-ammonia still process is carried out to solid-liquid separation, and solution enters the purification and impurity removal step;
(3) purification and impurity removal: add 1.28g potassium permanganate to stir 0.5h in the liquid after pre-ammonia still process, add a small amount of polyacrylamide solution (4mg/L) to filter, filtrate adds sodium sulphite by 1.2 times of the theoretical amount of precipitate C u, Cd, the required sodium sulphite of Pb, temperature, 70 ℃, churning time 2h, filter, and filtrate adds KMnO
4Consumption is 3.5 times of Fe amount, and 80 ℃ of temperature stir 1h (detecting Fe, Mn qualified), filter, and filtrate adds zinc powder by 2.5 times that replace Cu, Cd, the required theoretical zinc powder of Pb, stirs 30min, and temperature 60 C filters;
(4) refinement treatment, method is: in the liquid after purification and impurity removal is processed, add ammonium phosphate and tensio-active agent, add-on is to add 0.5kg ammonium phosphate, 40g surfactant SDS in the liquid after every cubic metre of purification and impurity removal is processed, and obtains refined liquid;
(5) ammonia still process crystallization: the gained refined liquid is inserted in ammonia distiller and carried out ammonia still process, vapour pressure import 0.6MPa/cm
2, 108 ℃ of solution temperatures, in the ammonia still process crystallisation process, detect at any time liquid zinc content in ammonia still, when the mass content 1% of zinc, add sodium hydroxide solution in ammonia still process equipment, the sodium hydroxide solution added is that to add the quality percentage composition be 3 liters of 30% sodium hydroxide solutions to every cubic metre of ammonia still process liquid, zinc quality percentage composition lower than 0.3% the time, finishes ammonia still process, and the emulsion obtained carries out solid-liquid separation, filter cake is by the washing of liquid-solid ratio 5:1 clear water, washing time 1h, refilter separation, obtains filter cake;
(6) drying and calcining: 105 ℃ of dryings of filter cake, obtain powder, through 350 ℃ of retort furnace calcining 60min, sampling detects and obtains purity ZnO%=99.82%; Median size 12.3nm (XRD live width method), specific surface area 112m
2The high-purity zinc oxide powder of/g.
Embodiment 3
Raw material: zinc oxide ore 3
#, its composition is: Zn13.6%. Fe18.67%. Si027.83%, its zinc phase composition of CaO29.92% are zinc carbonate 7.96%, zinc silicate 2. 21%. zinc sulphide 0.76%, automolite 2.67%.
Method for the preparation of high-purity zinc oxide:
(1) leaching: get 1t zinc oxide ore 3
#, leach as leaching agent with 3000L ammoniacal liquor-ammonium fluid; Wherein, NH in described leaching agent
3Volumetric molar concentration c (NH
3)=5.6mol/L, CO
3 2-Volumetric molar concentration c (CO
3 2-)=1.05 mol/L, add respectively Sodium Silicofluoride, SDS and Dicyanodiamide by the amount of the Dicyanodiamide of the surfactant SDS of adding 0.4kg, 0.05kg in every cubic metre of leaching agent, 0.5kg; When leaching, adopt ball milling, and guarantee that in ball mill, extraction time is 50 minutes, the ball mill outlet material is all by 140 mesh sieves, and adding up to leaching time is 3.5 hours, and temperature is that the amount of 25-40 ℃ of Sodium Silicofluoride adds Sodium Silicofluoride in leaching agent; Temperature is 25-40 ℃; After solid-liquid separation, in gained zinc ammonia complex liquid, zinc is 119.95 kilograms; The leaching yield of zinc oxide ore zinc is 88.19%;
(2) pre-ammonia still process: leaching liquid is heated to 92 ℃, remove the part free ammonia, steam while to ammonia concentration in liquid, being 3.2mol/L, then add the ratio of 2.6kg to add ammonium persulphate in every cubic metre of leaching liquid, liquid after pre-ammonia still process is carried out to solid-liquid separation, and solution enters the purification and impurity removal step;
(3) purification and impurity removal: add 3.6kg potassium permanganate to stir 0.8h in the liquid after pre-ammonia still process, add a small amount of polyacrylamide solution (4mg/L) to filter, filtrate adds sodium sulphite by 1.2 times of the theoretical amount of precipitate C u, Cd, the required sodium sulphite of Pb, temperature, 70 ℃, churning time 2h, filter, and filtrate adds KMnO
4Consumption is 3.5 times of Fe amount, and 80 ℃ of temperature stir 1h (detecting Fe, Mn qualified), filter, and filtrate adds zinc powder by 2.5 times that replace Cu, Cd, the required theoretical zinc powder of Pb, stirs 30min, and temperature 60 C filters;
(4) refinement treatment, method is: in the liquid after purification and impurity removal is processed, add ammonium phosphate and tensio-active agent, add-on is to add 0.8kg ammonium phosphate, 30kg surfactant SDS in the liquid after every cubic metre of purification and impurity removal is processed, and obtains refined liquid;
(5) ammonia still process crystallization: the gained refined liquid is inserted in ammonia distiller and carried out ammonia still process, vapour pressure import 0.8MPa/cm
2108 ℃ of solution temperatures, in the ammonia still process crystallisation process, detect at any time liquid zinc content in ammonia still, when the mass content of zinc 1.5% the time, in ammonia still process equipment, add sodium hydroxide solution, the sodium hydroxide solution added is that to add the quality percentage composition be 5 liters of 30% sodium hydroxide solutions to every cubic metre of ammonia still process liquid, zinc quality percentage composition is lower than 0.3% the time, the emulsion that end ammonia still process obtains carries out solid-liquid separation, and filter cake is by the washing of liquid-solid ratio 5:1 clear water, washing time 1h, refilter separation, obtain filter cake;
(6) drying and calcining: 105 ℃ of dryings of filter cake, obtain powder, through 400 ℃ of retort furnace calcining 80min, sampling detects and obtains purity ZnO%=99.83%; Median size 12.5nm (XRD live width method), specific surface area 107m
2The high-purity zinc oxide powder of/g.