阅读说明：本技术 一种以烷基化废硫酸生产碱式硫酸镁晶须的方法 (Method for producing basic magnesium sulfate whisker by using alkylation waste sulfuric acid ) 是由 黄祖强 张燕娟 曹小凤 胡华宇 覃宇奔 于 2019-04-24 设计创作，主要内容包括：本发明公开了一种以烷基化废硫酸制备碱式硫酸镁晶须的方法,包括如下步骤：(1)以烷基化废硫酸和氧化镁矿制备硫酸镁溶液；(2)硫酸镁溶液的催化氧化降解脱色；(3)水热法制备碱式硫酸镁晶须。本发明对烷基化废酸进行了资源化利用及无害化处理研究,以该废酸和氧化镁为原料,机械活化固相法制备的木质纤维素酯为氧化催化剂,模拟类芬顿试剂对硫酸镁溶液的有机杂质进行氧化降解脱色,然后采用水热法制备出长径比为80-150的碱式硫酸镁晶须产品。(The invention discloses a method for preparing basic magnesium sulfate whiskers by using alkylated waste sulfuric acid, which comprises the following steps: (1) preparing magnesium sulfate solution by using alkylated waste sulfuric acid and magnesium oxide ore; (2) carrying out catalytic oxidative degradation and decoloration on a magnesium sulfate solution; (3) preparing basic magnesium sulfate crystal whisker by a hydrothermal method. According to the invention, resource utilization and harmless treatment research are carried out on alkylated waste acid, the waste acid and magnesium oxide are used as raw materials, the lignocellulose ester prepared by a mechanical activation solid phase method is used as an oxidation catalyst, a simulated Fenton-like reagent is used for carrying out oxidative degradation and decoloration on organic impurities in a magnesium sulfate solution, and then a hydrothermal method is adopted to prepare a basic magnesium sulfate whisker product with the length-diameter ratio of 80-150.)

1. A method for preparing basic magnesium sulfate whisker by using alkylation waste sulfuric acid is characterized by comprising the following steps: comprises the following steps of (a) carrying out,

(1) preparation of magnesium sulfate solution: adding the alkylated waste sulfuric acid into the magnesium oxide mineral powder feed liquid under the stirring state, completely reacting until the pH value is neutral, filtering while the mixture is hot, and collecting filtrate to obtain a black magnesium sulfate solution;

(2) degradation and decoloration of magnesium sulfate solution: adding a lignocellulose ester catalyst into a black magnesium sulfate solution, uniformly mixing, adding a proper amount of oxidant under a stirring state to perform catalytic oxidation degradation reaction and decolorization, filtering after the reaction is finished, collecting filtrate, and controlling different reaction times to obtain magnesium sulfate solutions with different degradation degrees;

(3) Preparing basic magnesium sulfate crystal whisker by a hydrothermal method: slowly dripping alkaline solution into magnesium sulfate solution with different degradation degrees to obtain emulsion; pouring the emulsion into a hydrothermal reaction device for hydrothermal synthesis reaction, and obtaining the basic magnesium sulfate whisker after the reaction is finished.

2. The method for preparing basic magnesium sulfate whiskers from alkylated waste sulfuric acid according to claim 1, wherein: the stoichiometric ratio of the alkylated waste sulfuric acid to the magnesium oxide ore powder in the step (1) is 1: 1.

3. The method for preparing basic magnesium sulfate whiskers from alkylated waste sulfuric acid according to claim 1, wherein: in the step (2), the catalytic degradation reaction temperature is 30-80 ℃, and the reaction time is 30-180 min.

4. The method for preparing basic magnesium sulfate whiskers from alkylated waste sulfuric acid according to claim 1, wherein: and (3) carrying out a TOC test on the magnesium sulfate filtrate after the degradation reaction in the step (2), wherein the TOC is controlled to be below 100 mg/L.

5. The method for preparing basic magnesium sulfate whiskers from alkylated waste sulfuric acid according to claim 1, wherein: the oxidant in the step (2) is any one of hydrogen peroxide, chlorine dioxide, sodium hypochlorite and ozone.

6. The method for preparing basic magnesium sulfate whiskers from alkylated waste sulfuric acid according to claim 1, wherein: mg in the step (3)²⁺The concentration is 0.5-2.0 mol/L.

7. The method for preparing basic magnesium sulfate whiskers from alkylated waste sulfuric acid according to claim 1, wherein: the temperature of the hydrothermal reaction in the step (3) is 160-220 ℃, the hydrothermal time is 3-9 hours, and the stirring speed is 200-700 rpm.

8. The method for preparing basic magnesium sulfate whiskers from alkylated waste sulfuric acid according to claim 1, wherein: and (3) the alkaline solution is any one of ammonia water, sodium hydroxide and potassium hydroxide.

9. The method for preparing basic magnesium sulfate whiskers from alkylated waste sulfuric acid according to claim 1, wherein: and (4) washing a product obtained after the hydrothermal reaction in the step (3) by using deionized water and ethanol, and drying.

Technical Field

The invention belongs to the field of resource utilization of hazardous wastes, and particularly relates to a method for preparing basic magnesium sulfate whiskers by using alkylated waste sulfuric acid.

Background

With the international improvement of the requirements on fuel oil, the existing oil refinery widely adopts an alkylation method to produce isooctane, and the yield is increased rapidly. When an alkylation device is used for processing and producing high-octane alkylated gasoline, sulfuric acid with the concentration of 98% is used as a catalyst, 80-100 kg of waste sulfuric acid is produced every 1 ton of alkylated gasoline, and the waste sulfuric acid contains about 90% of sulfuric acid, about 7% of organic matters and about 3% of water. The organic substances are mainly high molecular olefins, dienes, alkyl sulfonic acids, sulfate esters, sulfides and the like, and the substances are dark in color, thick in texture, pungent in smell and difficult to completely remove from sulfuric acid. The existing mature treatment technology mainly comprises the steps of cracking and regenerating sulfuric acid for recycling, but has huge equipment investment, high cost and huge loss for treating each ton of waste sulfuric acid, great pressure is brought to the cost and the environment of a production enterprise, and the biggest problem which troubles the production of the enterprise is solved. Other treatment processes such as extraction and the like exist, but the recovery cost of the extraction solvent is high, the content of sulfuric acid is low, and no enterprise with application is found. In addition, the production of ammonium sulfate, magnesium sulfate, activated clay, precipitated white carbon black, petroleum rust inhibitor and the like by using the alkylated waste sulfuric acid is also researched, but because organic matters in the waste sulfuric acid cannot be effectively degraded and removed, the product has strong pungent smell, a high-purity product is difficult to obtain, the added treating agent is easy to cause secondary pollution, and the mother liquor is difficult to recycle. Therefore, at present, the alkylation waste sulfuric acid still cannot be effectively treated, a large amount of pressure is accumulated in production enterprises, the enterprises are exposed to the risk of production halt, and huge economic losses are brought to the enterprises.

Basic Magnesium Sulfate whiskers (abbreviated as MHSHw) have the appearance of white powders, the crystal shape of which is needle-like or fibrous and which have<0.1g/cm³Has an apparent density of 2.3 and an oil absorption of 500mL/100g and<10m²specific surface area in g. The diameter of the fibrous whisker is less than 1 μm, the fiber length is 10-100 μm, and the aspect ratio is 50-100. The basic magnesium sulfate whiskers have affinity to both water and organic solvents. Due to the presence of water of crystallization, its use temperature is relatively low compared to other whiskers, and most of it is below 250 ℃. At the same time, due to the presence of water of crystallization, alkaliThe magnesium sulfate whisker also has excellent flame retardant property and smoke suppression property. The basic magnesium sulfate whisker is a novel inorganic flame retardant material for reinforcing fiber, and the structure of the basic magnesium sulfate whisker is single crystal. Compared with composite plastic, the reinforced and flame-retardant plastic has more obvious reinforcing and flame-retardant effects. The method can manufacture parts with high deformation temperature, so that the surfaces of the parts are smooth and attractive, the proportion of the parts can be reduced, and the method is non-toxic and environment-friendly. The special and fine single crystal fiber whiskers are particularly suitable for reinforcing and strengthening small parts and ultrathin parts, and the effect is obvious. The whisker product not only has good scratch and skid resistance, but also meets the requirements of spraying or other engineering plastics on automobiles. When the whiskers are used as a flame retardant, the temperature thereof is higher than that of aluminum hydroxide, and therefore smoke can be suppressed and dripping can be prevented.

The research status of the basic magnesium sulfate whisker is as follows:

in 1982, Thugu discovered basic magnesium sulfate whiskers, one form of which was xMgSO₄·yMg(OH)₂·zH₂And O. In the following studies, after many years of diligent research, it was found that the following forms of basic magnesium sulfate whiskers exist: 153. 213, 152, etc.

In many reports on the synthesis of magnesium sulfate whiskers, MgSO is generally used as a synthesis source₄And MgO, MgSO₄And NaOH, MgSO₄And Mg (OH)₂NaOH and MgSO₄Is carried out in an aqueous solution. Calcining magnesite, adding sodium sulfate and MgSO₄And aqueous NaOH solution, MgO and MgSO₄The mixture of (2) is subjected to a hydrothermal synthesis reaction.

Current research and development at home and abroad:

gushuyuan, etc. uses bittern and industrial ammonia water as raw material, prepares and analyzes the content of magnesium hydroxide filter cake in it according to different proportions and MgSO₄·7H₂And mixing the O solution, putting the mixture into a reaction kettle, and carrying out hydrothermal reaction to obtain the basic magnesium sulfate whisker. Different single-factor conditions are set, and the influence of concentration, material proportion, time, temperature and rotating speed on the production of the basic magnesium sulfate whisker is researched. Under the optimal process conditions, the obtained product is MgSO₄·5Mg(OH)₂·3H₂O, the length of the whisker is about 18-60 μm, and the diameter is less than 1.0 μm.

Liu Feng is mainly MgSO ₄And NaOH are used as raw materials, the basic magnesium sulfate whisker is prepared by a hydrothermal method, and the appearance that different products can be formed due to different solution compositions is shown. The influence of concentration, material ratio, temperature, time and rotating speed on the generation of the basic magnesium sulfate whisker is researched. Under the optimal reaction condition, the magnesium oxysulfate whisker is prepared, the diameter of the whisker is 0.6-1 μm, and the length of the whisker is 18-30 μm.

Wujian pine etc. uses butanol as raw material, and adopts frequency conversion microwave heating and hydrothermal reaction to obtain the invented basic magnesium sulfate whisker with average length, complete crystal form, good dispersibility and smooth surface. The final whisker has a diameter of about 0.7 to 1.1 μm and a length of about 50 to 100 μm.

Ren chang et al is H₂SO₄To extract Mg from the boric sludge²⁺The precipitating agent is Na (OH)₂And obtaining the basic magnesium sulfate whisker. Varying the ratio of the concentrations of H₂SO₄Mixing the mixture into borax mud, reacting for a certain time, and standing and separating the product. Adding ammonium persulfate and magnesium oxide into the separated leaching solution, filtering to obtain MgSO₄And (3) solution. In Mg (OH)₂Adding MgSO dropwise into the solution₄Stirring the solution, uniformly mixing, putting into a reaction kettle, cooling the product to room temperature after the constant-temperature reaction is finished, and performing suction filtration, washing and drying on the precipitate to finally obtain the whisker product.

In order to utilize the magnesium sulfate solution prepared from the alkylated waste acid and reduce the production cost for preparing the basic magnesium sulfate whisker, the invention adopts the magnesium sulfate solution produced from the alkylated waste acid and magnesium oxide mineral powder and ammonia water as raw materials to prepare the basic magnesium sulfate whisker, and fully utilizes the alkylated waste sulfuric acid to produce a product with high added value.

Disclosure of Invention

Aiming at the current treatment situation of the existing alkylation waste sulfuric acid, the invention aims to provide a method for producing basic magnesium sulfate whiskers with high added value by directly utilizing a magnesium sulfate solution treated by a lignocellulose ester oxidation catalyst on the basis of research on catalytic treatment of alkylation waste sulfuric acid by lignocellulose ester.

The purpose of the invention is realized by the following technical scheme:

a method for preparing basic magnesium sulfate whisker by using alkylation waste sulfuric acid comprises the following steps,

(1) preparation of magnesium sulfate solution: adding the alkylated waste sulfuric acid into the magnesium oxide mineral powder feed liquid under the stirring state, completely reacting until the pH value is neutral, filtering while the mixture is hot, and collecting filtrate to obtain a black magnesium sulfate solution;

(2) degradation and decoloration of magnesium sulfate solution: adding a lignocellulose ester catalyst into a black magnesium sulfate solution, uniformly mixing, adding a proper amount of an oxidant under a stirring state to perform catalytic oxidation degradation reaction and decolorization, filtering after the reaction is finished, and collecting filtrate; magnesium sulfate solutions with different degradation degrees are obtained by controlling different reaction times;

(3) Preparing basic magnesium sulfate crystal whisker by a hydrothermal method: slowly dripping alkaline solution into magnesium sulfate solution with different degradation degrees to obtain emulsion; pouring the emulsion into a hydrothermal reaction device for hydrothermal synthesis reaction, and obtaining the basic magnesium sulfate whisker after the reaction is finished.

Preferably, the stoichiometric ratio of the alkylation waste sulfuric acid to the magnesium oxide ore powder in the step (1) is 1: 1.

Preferably, in the step (2), the catalytic degradation reaction temperature is 30-80 ℃, and the reaction time is 30-180 min.

Preferably, the magnesium sulfate filtrate after the degradation reaction in the step (2) is subjected to a TOC test, and the TOC is controlled to be less than 100 mg/L.

Preferably, in the step (2), the oxidant is any one of hydrogen peroxide, chlorine dioxide, sodium hypochlorite and ozone.

Preferably, in the step (3), Mg is used²⁺The concentration is 0.5-2.0 mol/L.

Preferably, the hydrothermal reaction in the step (3) has a temperature of 160-220 ℃, a hydrothermal time of 3-9 hours, and a stirring speed of 200-700 rpm.

Preferably, in the step (3), the alkaline solution is any one of ammonia water, sodium hydroxide and potassium hydroxide.

Preferably, after the hydrothermal reaction in step (3) is completed, the product is washed with deionized water and ethanol, and dried.

The invention has the following beneficial effects:

1. the invention carries out resource utilization and harmless treatment research on the alkylated waste acid, takes the waste acid and magnesium oxide as raw materials, adopts lignocellulose ester prepared by a mechanical activation solid phase method as an oxidation catalyst, simulates Fenton-like reagent to carry out oxidative degradation and decoloration on organic impurities of magnesium sulfate solution, and then adopts a hydrothermal method to prepare a basic magnesium sulfate whisker product with the length-diameter ratio of 80-150.

2. The invention optimizes the related process flow, determines the optimal reaction condition, and adopts Mg²⁺The concentration is 1.0mol/L, the hydrothermal temperature is 180 ℃, the hydrothermal time is 5h, and when the stirring speed is 500r/min, 153 type basic magnesium sulfate whiskers with the shape uniform and complete and the length-diameter ratio of 80-150 can be prepared.

3. The method utilizes the waste alkylated sulfuric acid of the oil refinery to prepare the basic magnesium sulfate whisker with high value, realizes the reutilization of high-pollution waste of the oil refinery, effectively reduces the related treatment cost, avoids the generation of secondary pollution, solves the treatment problem of the alkylated sulfuric acid, and realizes green and environment-friendly production.

Drawings

FIG. 1 is a flow chart of the preparation of basic magnesium sulfate whisker.

FIG. 2 is an SEM image of the product obtained by hydrothermal reaction under different temperature conditions of the present invention, wherein (a) is 160 ℃, (b) is 180 ℃, (c) is 200 ℃, (d) is 220 ℃.

FIG. 3 is an XDR graph of the product obtained by hydrothermal reaction under different temperature conditions according to the present invention, wherein (a)160 ℃, (b)180 ℃, (c)200 ℃, (d)220 ℃.

Detailed Description

In order to make those skilled in the art better understand the technical solutions in the present application, the following will clearly and completely describe the technical solutions in the present application with reference to the embodiments, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and all other embodiments obtained by a person of ordinary skill in the art without making creative efforts based on the embodiments in the present application shall fall within the protection scope of the present application.