阅读说明：本技术 利用fcc废催化剂联合制备钾明矾和高含量镧、铈稀土复合盐的工艺 (Process for jointly preparing potassium alum and high-content lanthanum-cerium rare earth composite salt by using FCC (fluid catalytic cracking) waste catalyst ) 是由 杨高文 赵亮 王旭红 张新 孙鹏鹏 于 2019-09-20 设计创作，主要内容包括：本发明公开了利用FCC废催化剂联合制备钾明矾和高含量镧、铈稀土复合盐的工艺,所述工艺包括以下步骤：1)废催化剂烘干、筛分预处理；2)硫酸浸取废催化剂；3)氢氧化钾法制备镧、铈稀土复合盐；4)制备钾明矾；5)循环液处理。该工艺通过对FCC废催化剂的处理,既制备出了钾明矾和高含量镧、铈稀土复合盐,又实现了对该危废物的无害化、减量化处理,为FCC废催化剂的无害化处理和综合利用找到了一条合理有效的途径。(The invention discloses a process for jointly preparing potassium alum and high-content lanthanum and cerium rare earth composite salt by using FCC spent catalyst, which comprises the following steps: 1) drying and screening the waste catalyst for pretreatment; 2) leaching the waste catalyst with sulfuric acid; 3) preparing lanthanum-cerium rare earth composite salt by a potassium hydroxide method; 4) preparing potassium alum; 5) and (6) treating the circulating liquid. The process not only prepares potassium alum and high-content lanthanum and cerium rare earth composite salt, but also realizes harmless and quantitative reduction treatment of the hazardous waste through the treatment of the FCC waste catalyst, and a reasonable and effective way is found for the harmless treatment and the comprehensive utilization of the FCC waste catalyst.)

1. The process for jointly preparing potassium alum and high-content lanthanum and cerium rare earth composite salt by using the FCC spent catalyst is characterized by comprising the following steps of:

1) Drying and screening the waste catalyst: heating FCC spent catalyst in a drying oven, drying, taking out the spent catalyst, cooling to room temperature, and screening by using a 300-600 mesh sieve in a fume hood to remove large-particle stones to obtain fine powdery spent catalyst;

2) Sulfuric acid leaching of the spent catalyst: weighing the fine powdery waste catalyst treated in the step 1), measuring sulfuric acid, heating and stirring in a water bath, adding the weighed fine powdery waste catalyst when the temperature reaches 50-120 ℃, continuously stirring, supplementing water, continuously stirring, carrying out suction filtration on reaction slurry while the reaction slurry is hot, washing a filter cake with a proper amount of warm water until a washing liquid is clear, mixing the filtrate and the washing liquid, and carrying out constant volume in a volumetric flask to obtain a leaching solution;

3) preparing lanthanum-cerium-rare earth composite salt by a potassium hydroxide method: transferring the leachate obtained in the step 2) into a flask, setting the temperature to be 60-90 ℃, heating and stirring at the stirring speed of 400-450 r/min, slowly dropwise adding a KOH solution with the concentration of 30% by using a separating funnel, simultaneously measuring the change of the pH value of the system by using a pH meter, increasing the stirring speed of an electric stirrer, stirring at the stirring speed of 600-700 r/min, carrying out rapid stirring, stopping dropwise adding the KOH solution with the concentration of 30% when the pH is 1.0-1.7, allowing a rare earth double salt white precipitate to appear in a reaction solution, filtering the turbid rare earth double salt solution while the turbid solution is hot, retaining the filtrate, washing and drying the solid by using a proper amount of clear water, thus obtaining a white rare earth double salt mixture;

4) Preparing potassium alum: pouring the hot filtrate obtained in the step 3) back into the original flask for preparing the rare earth double salt, heating at 50-90 ℃, stirring, dropwise adding 30% potassium hydroxide solution again, reacting for 10-20min, pouring the reaction solution into the beaker, naturally cooling and crystallizing to separate out potassium alum solid, carrying out suction filtration on the obtained potassium alum solid, washing with proper amount of clear water, naturally drying, and weighing to obtain potassium alum; the suction filtration liquid is a circulating liquid, and the circulating liquid and the washing water in the step 3) and the step 4) can be used for preparing sulfuric acid in the step 2) or used as supplementary water to participate in the circulation of the filtrate;

5) Treating circulating liquid: and recycling the filtrate for 8 times, adding potassium hydroxide until the pH value is 7, and filtering to obtain high-content nickel salt filter residue and neutralizing clear liquid.

2. The process for jointly preparing potassium alum and high-content lanthanum and cerium rare earth composite salt by using the FCC spent catalyst according to claim 1, wherein the spent catalyst of the step 1) is heated in an oven for 1-2h at a temperature of 150-200 ℃.

3. the process for jointly preparing potassium alum and high-content lanthanum and cerium rare earth composite salt by using the FCC spent catalyst according to claim 1, wherein the initial concentration of the sulfuric acid in the step 2) is 6-9 mol/l.

4. The process for jointly preparing potassium alum and high-content lanthanum and cerium rare earth composite salt by using the FCC spent catalyst according to claim 1, wherein the whole reaction time of the step 2) is 4-9 h.

5. The process for jointly preparing potassium alum and high-content lanthanum and cerium rare earth composite salt by using the FCC spent catalyst according to claim 1, wherein the reaction time of the step 3) is 10-20min, and the reaction temperature is 60-90 ℃.

6. the process for jointly preparing potassium alum and high-content lanthanum and cerium rare earth composite salt by using the FCC spent catalyst according to claim 1, wherein the content of lanthanum sulfate and cerium sulfate composite salt in the white rare earth composite salt of the step 3) is more than 23%.

7. the process for jointly preparing potassium alum and high-content lanthanum and cerium rare earth composite salt by using the FCC spent catalyst according to claim 1, wherein the concentration of the heavy metal ions of nickel, lead, copper, zinc, manganese and chromium in the neutralized clear liquid in the step 5) is less than 0.1 mg/L.

Technical Field

The invention belongs to the technical field of harmless treatment and resource recycling, and particularly relates to a process for jointly preparing potassium alum and high-content lanthanum and cerium rare earth composite salt by using FCC (fluid catalytic cracking) waste catalyst.

Background

Catalytic cracking is an important component in the modern petroleum refining industry, which is particularly important in the chinese oil refining industry. Heavy oil requires the help of catalyst in the process of being changed into light oil through catalytic cracking, and simultaneously generates a large amount of waste catalyst (FCC) every year. In 2016, FCC waste catalyst is classified into HW50 dangerous waste solids in national hazardous waste records, so that the FCC waste catalyst cannot be randomly buried, even if the landfill cost is extremely high, the FCC waste catalyst is also a precious secondary resource raw material rich in elements such as aluminum, nickel, rare earth and the like, and if the FCC waste catalyst can be reasonably recycled, the FCC waste catalyst not only can bring good social benefits, but also can bring considerable economic benefits. The aluminum product is one of the important basic raw materials for national economic construction, the rare earth is an important strategic resource, the industrial value is extremely high, and in order to better protect the rare earth resource in China, the state continuously regulates the rare earth order, perfects the laws and regulations and simultaneously strengthens the management of recycling the rare earth resource.

At present, the research information on how to effectively treat the FCC spent catalyst is not much, and the method can be roughly divided into two aspects of source treatment and resource treatment. Zhangli and the like use FCC spent catalyst and carclazyte to prepare compound adsorbent refined lubricating oil, and when the effect of the compound adsorbent refined lubricating oil is the same as that of the carclazyte, the consumption of the carclazyte is reduced by 0.6 percent, and the yield of oil products is improved by 0.1 percent; ye Sishi et al use hydrochloric acid to leach FCC spent catalyst, organic solvent extracts rare earth elements, rare earth recovery rate reaches 85%; innocenzi and the like leach waste catalysts by using sulfuric acid, and the rare earth is precipitated by alkali, so that the recovery rate of lanthanum and cerium reaches 89% and 82% finally. But all have the pollution problems of secondary dangerous waste liquid and waste solid.

Disclosure of Invention

The purpose of the invention is as follows: the method can effectively treat the FCC waste catalyst, fully utilize the aluminum element in the waste catalyst, and simultaneously recover the rare earth elements of lanthanum and cerium with maximum efficiency. The waste catalyst is changed into valuable by a green chemical means, and the recycling of resources and zero emission of pollutants are promoted. The invention meets the requirements of fourteen-five plans in China, conforms to the times trend of environmental protection and sustainable development, and realizes the reduction of solid waste discharge. The invention can achieve the purposes of protecting the ecological environment and realizing economic sustainable development, and therefore, the invention provides a process for jointly preparing potassium alum and high-content lanthanum and cerium rare earth composite salt by using FCC waste catalyst.

In order to solve the technical problems, the invention adopts the following technical scheme: the process for jointly preparing potassium alum and high-content lanthanum and cerium rare earth composite salt by using the FCC spent catalyst comprises the following steps:

1) Drying and screening the waste catalyst: heating FCC spent catalyst in a drying oven, drying, taking out the spent catalyst, cooling to room temperature, and screening by using a sieve in a fume hood to remove large-particle stones to obtain fine powdery spent catalyst;

2) Sulfuric acid leaching of the spent catalyst: weighing the FCC spent catalyst treated in the step 1), measuring sulfuric acid, heating and stirring in a water bath, adding the weighed FCC spent catalyst when the temperature reaches 50-120 ℃, continuously stirring, replenishing water, continuously stirring, carrying out suction filtration on reaction slurry while the reaction slurry is hot, washing a filter cake with a proper amount of warm water until a washing liquid is clear, mixing the filtrate and the washing liquid, and fixing the volume to a volumetric flask;

3) Preparing lanthanum-cerium-rare earth composite salt by a potassium hydroxide method: transferring the leachate obtained in the step 2) into a flask, setting the temperature to be 60-90 ℃, heating and stirring, slowly dripping a KOH solution with the concentration of 30% by using a separating funnel, simultaneously measuring the change of the pH value of the system by using a pH meter, increasing the stirring speed of an electric stirrer, carrying out rapid stirring, stopping dripping the KOH solution with the concentration of 30% when the pH value is 1.0-1.7, allowing a white precipitate of the rare earth double salt to appear in the reaction solution, filtering the turbid solution of the rare earth double salt while hot, and washing and drying the solid by using a proper amount of clear water to obtain a white rare earth double salt mixture;

4) Preparing potassium alum: pouring the hot filtrate obtained in the step 3) back into the original flask for preparing the rare earth double salt, heating at 50-90 ℃, stirring, dropwise adding 30% potassium hydroxide solution again, reacting for 10-20min, pouring the reaction solution into the beaker, naturally cooling and crystallizing to separate out potassium alum solid, carrying out suction filtration on the obtained potassium alum solid, washing with proper amount of clear water, naturally drying, and weighing to obtain potassium alum; the suction filtration liquid is a circulating liquid, and the circulating liquid and the washing water in the step 3) and the step 4) can be used for preparing sulfuric acid in the step 2) or used as supplementary water to participate in the circulation of the filtrate;

5) Treating circulating liquid: and recycling the filtrate for 8 times, adding potassium hydroxide until the pH value is 7, and filtering to obtain high-content nickel salt filter residue and neutralizing clear liquid.

wherein, the filter residue with high content of nickel salt is processed by qualified enterprises, and the neutralized clear liquid is analyzed and detected by an ICP instrument, wherein the concentration of heavy metal ions such as nickel, lead, copper, zinc, manganese, chromium and the like is less than 0.5-2mg/L, which accords with the national urban new sewage discharge standard (GB8978-1996), and can also enter a circulating water system.

Wherein the heating time of the step 1) is 1-2h, and the temperature is 150-200 ℃.

wherein the initial concentration of the sulfuric acid in the step 2) is 6-9mol/l, the reaction temperature is 50-120 ℃, and the reaction time is 4-9 h.

Wherein, the reaction temperature is 60-90 ℃ when the lanthanum-cerium rare earth composite salt is prepared in the step 3), and the pH value of the solution is adjusted to 1.0-1.7 by using 30% potassium hydroxide solution.

Wherein, the content of lanthanum sulfate and cerium sulfate composite salt in the white rare earth composite salt is more than 23 percent.

Wherein, the concentration of heavy metal ions of nickel, lead, copper, zinc, manganese and chromium in the neutralized clear liquid in the step 5) is less than 0.1 mg/L.

Wherein, 130-160g of potassium alum can be prepared by every 100g of the waste catalyst.

The method takes FCC waste catalyst of certain petrochemical enterprises as raw material, transfers metal elements (aluminum, lanthanum, cerium, nickel and the like) in the FCC waste catalyst into solution by researching and leaching the FCC waste catalyst, firstly recovers rare earth and aluminum elements, produces sulfuric acid series rare earth double salt and potassium alum, and removes heavy metal elements such as nickel, iron and the like which seriously pollute water circulation and environment so as to realize water circulation.

Has the advantages that: the method has the greatest advantage that the leaching solution is creatively treated by a potassium hydroxide method, so that rare earth double salt and potassium alum products are obtained, the acidity of the system is neutralized, the pH value is increased, and convenience is brought to treatment of tailings and tail liquid in future. The invention uses sulfuric acid and potassium hydroxide to treat the waste catalyst which is buried all the time, the process of the invention is simple and easy to implement, the problem of waste liquid generated in the treatment process is fully considered, and new waste liquid and new pollution generated in the process are avoided; in addition, the invention also has the following advantages:

1. the invention can realize water circulation, reduce the discharge amount of waste water and save water resources.

2. The invention can circulate the alum filtrate for at least eight times, not only enrich nickel salt, but also ensure that the treated waste liquid can be discharged.

3. The invention can promote the recycling of waste resources, realize the comprehensive regeneration of dangerous waste catalysts and fill the blank of the domestic technology for treating the dangerous waste catalysts

4. the technology provided by the invention effectively eliminates the pollution of the waste catalyst to soil and water, is beneficial to reducing the environmental pollution problem nearby petrochemical enterprises, and realizes harmony between human and nature.

5. Compared with the potassium alum directly produced by using industrial raw materials in the prior art, the method has lower production cost and higher benefit.

6. The invention realizes green chemical reaction as far as possible in the technical process, achieves the aim of no three-waste discharge, and completely converts possible pollution source ions into useful chemical products.

7. The potassium alum product prepared by the method has high purity, excellent quality and high rare earth conversion rate.

8. The production process completely follows the national principle of 'harmlessness, reclamation and reduction' for hazardous waste treatment.

Drawings

FIG. 1 is a process flow diagram of the present invention.

Detailed Description

the invention is further described below with reference to the figures and examples.