Method for recovering zinc from zinc ferrite resource by using calcification ball-milling roasting-alkaline leaching method
阅读说明：本技术 利用钙化球磨焙烧-碱浸法从铁酸锌资源中回收锌的方法 (Method for recovering zinc from zinc ferrite resource by using calcification ball-milling roasting-alkaline leaching method ) 是由 张承龙 申宸昊 王瑞雪 马恩 白建峰 苑文仪 王景伟 于 2021-07-29 设计创作，主要内容包括：本发明属于湿法冶金和固体废物资源化技术领域,具体为一种利用钙化球磨焙烧-碱浸法从铁酸锌资源中回收锌的方法。包括以下步骤：(1)将铁酸锌资源和钙化剂混合后进行球磨反应,通过机械力作用促进铁酸锌矿相重构转化为氧化锌；(2)将球磨产物在氧化气氛下进行钙化焙烧,强化铁酸锌的矿相重构反应；(3)焙烧产物在碱溶液中浸出,使氧化锌溶解,固液分离后,得到锌滤液和浸出渣。本发明通过球磨处理降低了钙化焙烧所需的较高温度,在相对低的温度下使铁酸锌进行矿相重构转化为氧化锌,易于后续碱浸提取,浸出成本低、选择性好,且反应速度快,锌浸出率得到有效提高。(The invention belongs to the technical field of hydrometallurgy and solid waste recycling, and particularly relates to a method for recovering zinc from a zinc ferrite resource by using a calcification ball-milling roasting-alkaline leaching method. The method comprises the following steps: (1) mixing zinc ferrite resources with a calcification agent, carrying out ball milling reaction, and promoting the reconstruction of zinc ferrite ore phase to be converted into zinc oxide by mechanical force; (2) carrying out calcification roasting on the ball-milled product in an oxidizing atmosphere to strengthen the mineral phase reconstruction reaction of the zinc ferrite; (3) leaching the roasted product in an alkali solution to dissolve zinc oxide, and performing solid-liquid separation to obtain zinc filtrate and leaching residues. The invention reduces the higher temperature required by calcification roasting through ball milling treatment, leads the zinc ferrite to carry out ore phase reconstruction and convert into zinc oxide at relatively low temperature, is easy for subsequent alkaline leaching extraction, has low leaching cost, good selectivity and fast reaction speed, and effectively improves the zinc leaching rate.)
1. A method for recovering zinc from zinc ferrite resources by using a calcification ball-milling roasting-alkaline leaching method is characterized by comprising the following specific steps:
(1) uniformly mixing zinc ferrite resources with a calcification agent, performing ball milling activation, and promoting the reconstruction of zinc ferrite ore phases to be converted into zinc oxide by the action of mechanical force;
(2) carrying out calcification roasting on the ball-milling activation product obtained in the step (1) in an oxidizing atmosphere to further strengthen the mineral phase reconstruction reaction of zinc ferrite;
(3) leaching the calcified roasting product obtained in the step (2) in an alkali solution to dissolve zinc oxide, and performing solid-liquid separation to obtain a zinc-containing filtrate and leaching residues.
2. The method for recovering zinc from a zinc ferrite resource by using the calcification ball-milling roasting-alkaline leaching method as recited in claim 1, wherein the zinc ferrite resource is one or more selected from the group consisting of steel plant dust, zinc-containing leaching slag, and lead-zinc smelting slag, in which zinc ferrite is a main zinc-containing phase.
3. The method for recovering zinc from a zinc ferrite resource by using the calcification ball-milling roasting-alkaline leaching method as claimed in claim 1, wherein in the step (1), the calcification agent is one or more of calcium oxide, calcium hydroxide or calcium carbonate.
4. The method for recovering zinc from a zinc ferrite resource by using the calcification ball-milling roasting-alkaline leaching method as claimed in claim 3, wherein the dosage of the calcification agent is calculated by CaO, and the molar ratio of the calcification agent to the zinc ferrite is 2.5: 1-4.5: 1.
5. the method for recovering zinc from a zinc ferrite resource by using the calcification ball-milling roasting-alkaline leaching method as claimed in claim 1, wherein in the step (1), the ball-milling activation is performed in a planetary ball mill, the mass ratio of ball materials is 5: 1-10: 1, the ball-milling rotation speed is 400-500 rpm, and the ball-milling time is 120-180 min.
6. The method for recovering zinc from a zinc ferrite resource by using the calcification ball-milling roasting-alkali leaching method as recited in claim 1, wherein in the step (2), the calcification roasting is performed in a muffle furnace, the roasting temperature is 850-900 ℃, and the roasting time is 120-180 min.
7. The method for recovering zinc from a zinc ferrite resource by using the calcification ball-milling roasting-alkali leaching method as defined in claim 1, wherein in the step (3), the volume-to-mass ratio of the alkali solution to the calcification roasting product is 8: 1-30: 1mL/g, the leaching temperature is 60-80 ℃, and the leaching time is 120-180 min.
8. The method for recovering zinc from a zinc ferrite resource by using the calcification ball-milling roasting-alkaline leaching method as defined in claim 1, wherein in the step (3), the alkali solution is a sodium hydroxide solution, and the concentration is 6-10 mol/L.
Technical Field
The invention relates to a method for recovering zinc from zinc ferrite resources by using a calcification ball-milling roasting-alkaline leaching method, belonging to the technical field of hydrometallurgy and solid waste recycling.
Background
The zinc alloy has the advantages of low cost, good corrosion resistance and the like, and is widely used in production and life; the recycling of secondary resources, particularly the recycling of dust in zinc-containing steel plants, is an important way for realizing the recycling of resources and the sustainable development of roads.
According to different zinc element contents in the dust of the steel plant, different resource treatment methods are adopted, the dust with low zinc content is returned to the steel plant for recycling, and the dust with high zinc content can be extracted into high-purity metal zinc by a wet method or a fire method. The recycling of the steel plant is to directly add the dust into the procedures of sintering pellets or steelmaking and the like, the iron recovery effect in the dust is reduced due to low iron grade and high zinc content of the dust in the sintering pellet treatment, and the sinter ore with high zinc content can bring harm to the subsequent blast furnace operation; in the steelmaking treatment, dust and carbon with low zinc content are sprayed into a converter or an electric furnace, zinc is reduced and volatilized at high temperature and enters a smoke dust system, and iron oxide enters slag and molten steel to be utilized, but the method is only suitable for dust with low lead and zinc content and high iron content. Reducing agent or chlorinating agent is added in the pyrogenic process, the reducing agent reduces zinc in the dust into metal zinc, and the metal zinc is volatilized, separated and enriched; the chlorinating agent chloridizes the lead and zinc and volatilizes and removes the lead and zinc. The problems of high energy consumption, large investment, environmental pollution and the like exist in the pyrogenic process treatment. The wet treatment utilizes roasting, leaching and the like to treat high-zinc dust, and comprises acid leaching, alkali leaching and the like. The leaching of strong acid solution is easy to generate poisonous and harmful gases such as chlorine and the like, the weak acid solution cannot react with zinc ferrite in dust, the efficiency is low, and meanwhile, impurity elements such as iron, calcium and the like are completely dissolved, and the zinc is difficult to be effectively separated. Compared with the acid leaching process, the alkaline leaching process has lower corrosion degree on equipment, hardly leaches iron and has better selectivity.
The zinc ferrite resource is solid waste which can be recycled, such as steel plant dust, zinc-containing leaching slag, lead-zinc smelting slag and the like, wherein zinc ferrite is used as a main zinc-containing phase. The zinc ferrite is in a spinel structure, the chemical bond between ions is firm, the atom stacking polymerization is compact, the physical and chemical properties are stable, and the zinc ferrite becomes a main restriction factor for the wet recycling of zinc ferrite resources. Therefore, it is worth researching to find a process route for pre-treating zinc ferrite resources and realizing efficient leaching and recovery of zinc.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention aims to provide a method for selectively leaching zinc in a zinc ferrite resource in an alkaline solution through ball milling-roasting pretreatment.
According to the invention, a calcification agent is added into a zinc ferrite resource, the zinc ferrite and calcium oxide in the calcification agent are converted into zinc oxide which is easy to leach through planetary ball milling combined roasting treatment, zinc in the zinc ferrite resource is recovered by adopting an alkali solution selective leaching method, the zinc ferrite and the calcium oxide can be converted at high temperature to generate zinc oxide, the reaction activation energy is reduced through mechanical activation, and the zinc ferrite can be converted through roasting at relatively low temperature. The chemical reactions mainly involved in the invention are as follows:
ZnFe2O4+2CaO＝Ca2Fe2O5+ZnO
ZnO+2OH-＝ZnO2 2-+H2O
the zinc ferrite resource mainly comprises iron oxide, CaO and SiO2After the treatment scheme is adopted, iron oxide exists in leaching slag, and calcium oxide can be used as calcificationThe agent reacts with zinc ferrite, and the silicon dioxide reacts with sodium hydroxide to generate sodium silicate which exists in the leaching solution.
The technical scheme of the invention is realized as follows:
the invention provides a method for recovering zinc from zinc ferrite resources by using a calcification ball-milling roasting-alkaline leaching method, which comprises the following steps:
(1) uniformly mixing zinc ferrite resources and a calcification agent, and then performing ball milling activation in a planetary ball mill, wherein the particle size of the material is reduced, the specific surface area is increased, and the crystal lattice generates defects under the action of mechanical force, so that the internal energy is increased, the reaction activity is improved, and the reconstruction of a zinc ferrite mineral phase is promoted to be converted into zinc oxide;
(2) carrying out calcification roasting on the ball-milling activation product obtained in the step (1) in an oxidizing atmosphere to further strengthen the mineral phase reconstruction reaction of zinc ferrite;
(3) leaching the calcified roasting product obtained in the step (2) in an alkali solution to dissolve zinc oxide, and performing solid-liquid separation to obtain a zinc-containing filtrate and leaching residues.
Preferably, the zinc ferrite resource is selected from one or more of steel plant dust, zinc-containing leaching slag and lead-zinc smelting slag which take zinc ferrite as a main zinc-containing phase.
Preferably, in the step (1), the calcification agent is one or more of calcium oxide, calcium hydroxide or calcium carbonate; the dosage of the calcification agent is calculated by CaO, and the mol ratio of the calcification agent to the zinc ferrite is 2.5: 1-4.5: 1.
preferably, in the step (1), ball milling activation is carried out in a planetary ball mill, the mass ratio of ball materials is 5: 1-10: 1, the ball milling rotation speed is 400-500 rpm, and the ball milling time is 120-180 min.
Preferably, in the step (2), the calcification roasting is carried out in a muffle furnace, the roasting temperature is 850-900 ℃, and the roasting time is 120-180 min.
Preferably, in the step (3), a stirring leaching mode is adopted, and a leaching device is closed.
Preferably, in the step (3), the volume mass ratio of the alkali solution to the calcified roasting product is 8: 1-30: 1mL/g, leaching temperature of 60-80 ℃, and leaching time of 120-180 min.
Preferably, in the step (3), the alkali solution is a sodium hydroxide solution, and the concentration is 6-10 mol/L.
Compared with the prior art, the invention has the beneficial technical effects that:
(1) according to the method for recovering zinc from the zinc ferrite resource by using the calcification ball-milling roasting-alkaline leaching method, the particle size of the material is reduced, the specific surface area is increased, and the defects are generated on crystal lattices under the action of mechanical force through ball-milling activation, so that the internal energy is increased, the reaction activity is improved, the reconstruction of a zinc ferrite ore phase is promoted to be converted into zinc oxide, and the roasting temperature required by the subsequent reconstruction, reinforcement and conversion of the zinc ferrite ore phase is effectively reduced.
(2) According to the method for recovering zinc from the zinc ferrite resource by using the calcification ball-milling roasting-alkali leaching method, the zinc ferrite resource is subjected to mineral reconstruction and is converted into zinc oxide through the calcification ball-milling roasting, the subsequent alkali leaching extraction is easy, the leaching cost is low, the selectivity is good, the adopted calcification agent is cheap and easy to obtain, compared with the pyrogenic carbonization-reduction method, coke or reducing coal is not required to be added as a reducing agent, the reaction rate is high, and the zinc leaching rate can reach more than 80%.
(3) The method selectively dissolves zinc oxide, hardly leaches iron, and has the advantages of good selectivity, quick leaching effect, ideal treatment effect, environmental protection, economy and saving because iron oxide exists in leaching slag.
(4) The invention provides a method for recovering zinc from zinc ferrite resources by using a calcification ball-milling roasting-alkaline leaching method, wherein the main component of leaching residues is Ca2Fe2O5The zinc-rich zinc oxide can be used as a dephosphorization agent or a raw material of a sintering plant, reduces environmental pollution caused by dust of the steel plant, can be recycled after the zinc-rich zinc.
Drawings
FIG. 1 is a process flow chart of recovery of zinc from zinc ferrite resources by using a calcification ball-milling roasting-alkaline leaching method in example 1 of the present invention.
FIG. 2 is an XRD pattern of a ball-milled, calcined product of example 1.
Fig. 3 is an XRD pattern of the ball-milled calcined product of comparative example 1.
Fig. 4 is an XRD pattern of the ball-milled calcined product of comparative example 3.
Detailed Description
The technical solution of the present invention will be described in detail with reference to the accompanying drawings and embodiments.
FIG. 1 is a process flow chart of recovery of zinc from zinc ferrite resources by using a calcification ball-milling roasting-alkaline leaching method in example 1 of the present invention.
Example 1
Zinc ferrite (purity 99%) is used as a raw material, and the mass fractions of main elements are as follows:
the extraction process is shown in figure 1: according to the mol ratio of CaO to zinc ferrite of 4.2:1 adding calcium oxide into zinc ferrite, uniformly mixing, putting into a planetary ball milling tank, adding ball milling beads according to the ball material mass ratio of 6: 1, and ball milling for 180min by a planetary ball mill at the rotating speed of 500 rpm. And placing the ball-milled product in a muffle furnace for calcification roasting, and completing phase reconstruction, wherein the roasting temperature is 900 ℃ and the roasting time is 120 min. And (3) naturally cooling the roasted product, and then performing alkaline leaching treatment, wherein the alkaline leaching system is as follows: the liquid-solid ratio is 8mL/g, the leaching temperature is 80 ℃, the leaching time is 180min, and the leaching solution adopts 6mol/L NaOH solution. After the leaching solution is filtered, the leaching rate of zinc is 83.4 percent. The XRD pattern of the ball-milled calcination product is shown in figure 2.
Example 2
The zinc-containing dust of a certain steel plant is taken as a raw material, and the total Zn content is 9.6 percent (wherein ZnFe is used2O4The Zn content in the form of the calcium oxide accounts for 45.5 percent, and the other zinc oxide exists basically), calcium oxide is added into the dust of the steel plant according to the mol ratio of CaO to zinc ferrite of 3.8:1, the mixture is uniformly mixed and then put into a planetary ball milling tank, ball milling beads are added according to the mass ratio of the ball materials of 6: 1, and the planetary ball milling machine performs ball milling for 180 minutes at the rotating speed of 500 rpm. And placing the ball-milled product in a muffle furnace for calcification roasting, and completing phase reconstruction, wherein the roasting temperature is 850 ℃ and the roasting time is 120 min. And (3) naturally cooling the roasted product, and then performing alkaline leaching treatment, wherein the alkaline leaching system is as follows: the liquid-solid ratio is 8mL/g, the leaching temperature is 80 ℃, and the leaching is carried outThe extraction time is 180min, and the leaching solution adopts 6mol/L NaOH solution. After the leaching solution is filtered, the leaching rate of zinc is 92.5 percent, and the leaching rate of iron is 0.5 percent.
Comparative example 1
Zinc ferrite (purity 99%) is used as a raw material, and the mass fractions of main elements are as follows:
adding calcium oxide into zinc ferrite according to the mol ratio of CaO to zinc ferrite of 4.2:1, uniformly mixing, placing in a muffle furnace for calcification roasting, and completing phase reconstruction, wherein the roasting temperature is 900 ℃, and the roasting time is 120 min. And (3) naturally cooling the roasted product, and then performing alkaline leaching treatment, wherein the alkaline leaching system is as follows: the liquid-solid ratio is 8mL/g, the leaching temperature is 80 ℃, the leaching time is 180min, and the leaching solution adopts 6mol/L NaOH solution. After the leaching solution is filtered, the leaching rate of zinc is 15.4%. The XRD pattern of the calcined product is shown in figure 3.
Comparative example 2
Zinc ferrite (purity 99%) is used as a raw material, and the mass fractions of main elements are as follows:
adding calcium oxide into zinc ferrite according to the mol ratio of CaO to zinc ferrite of 4.2:1, uniformly mixing, placing in a muffle furnace for calcification roasting, and completing phase reconstruction, wherein the roasting temperature is 1200 ℃, and the roasting time is 120 min. And (3) naturally cooling the roasted product, and then performing alkaline leaching treatment, wherein the alkaline leaching system is as follows: the liquid-solid ratio is 8mL/g, the leaching temperature is 80 ℃, the leaching time is 180min, and the leaching solution adopts 6mol/L NaOH solution. After the leaching solution is filtered, the leaching rate of zinc is 65.5 percent.
Comparative example 3
Zinc ferrite (purity 99%) is used as a raw material, and the mass fractions of main elements are as follows:
adding calcium oxide into zinc ferrite according to the mol ratio of CaO to zinc ferrite of 4.2:1, uniformly mixing, putting into a planetary ball milling tank, adding ball milling beads according to the mass ratio of balls to materials of 6: 1, and ball milling for 180min by a planetary ball mill at the rotating speed of 500 rpm. And (3) carrying out alkaline leaching treatment on the ball-milled product, wherein the alkaline leaching system is as follows: the liquid-solid ratio is 8mL/g, the leaching temperature is 80 ℃, the leaching time is 180min, and the leaching solution adopts 6mol/L NaOH solution. After the leaching solution is filtered, the leaching rate of zinc is 4.9 percent. The XRD pattern of the ball-milled product is shown in figure 4.
According to the results of comparative example 1, comparative example 2, comparative example 3 and example 1, zinc ferrite and calcium oxide can be converted into zinc oxide at high temperature, the activation energy of the reaction can be effectively reduced through mechanical ball milling, and high-efficiency conversion can be realized through roasting at relatively low temperature.
The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above-described embodiments. Modifications and variations that may occur to those skilled in the art without departing from the spirit and scope of the invention are to be considered as within the scope of the invention.