CN104495881A

CN104495881A - Process for preparing high-purity silicon steel magnesium oxide from magnesium hydroxide

Info

Publication number: CN104495881A
Application number: CN201410798736.8A
Authority: CN
Inventors: 徐徽; 廖浩然; 程俊峰; 李贵
Original assignee: Central South University
Current assignee: Central South University
Priority date: 2014-12-19
Filing date: 2014-12-19
Publication date: 2015-04-08
Anticipated expiration: 2034-12-19
Also published as: CN104495881B

Abstract

The invention discloses a process for preparing high-purity silicon steel magnesium oxide from magnesium hydroxide. The process comprises the following steps: performing light roasting on magnesium hydroxide, adding magnesium hydroxide into water, heating to hydrate, further cooling, and slowly adding an ammonium bicarbonate solution into water to carbonize, thereby obtaining a suspension;filtering the suspension, washing and drying the residues obtained after filtration, and further roasting at high temperature, thereby obtaining the high-purity silicon steel magnesium oxide. According to the process, magnesium hydroxide is adopted as a raw material to prepare silicon steel magnesium oxide which is regular in morphology and high in purity, the process procedure is short, and the prepared magnesium oxide is stable in quality and high in production efficiency, and the industrial production requirements are met.

Description

A kind of by the magnesian technique of magnesium hydroxide preparation HIGH-PURITY SILICON grade of steel

Technical field

The present invention relates to a kind of by the magnesian technique of magnesium hydroxide preparation HIGH-PURITY SILICON grade of steel, belong to magnesium oxide preparing technical field.

Background technology

In China's Qinghai Chaerhan salt lakes, magnesium resource is abnormal abundant, and can produce a large amount of magnesium chloride hexahydrates while exploitation Cha Er Han Salt Lake potash fertilizer, causes magnesium evil.Ammonia process has been sunk magnesium technique and has been used for scale operation magnesium hydroxide by current Qinghai Western Magnesium Technology Co., Ltd., in order to better develop the value of magnesium compound, developing and a kind ofly by the magnesian technique of magnesium hydroxide preparation HIGH-PURITY SILICON grade of steel, there are very large economic interests.

Silicon-steel grade magnesium oxide is the one of light magnesium oxide, its purity requirement>=98%, and the suspension property in water is good, aquation rate is low, in production grain-oriented Si steel sheet process, silicon-steel grade magnesium oxide is coated between siliconized plate with the form of suspension, forms MgSiO in high-temperature annealing process with silicate ₃insulation layer, and the effect playing dephosphorization, desulfurization.The magnesium resource comparatively horn of plenty of China, but the high product of added value is little.Along with the development of China's science and technology, the large-lot producer such as Wuhan Iron and Steel Plant, Baosteel has started to produce orientating type siliconized plate, domestic only have Shanghai Zhen Taideng enterprise can produce the silicon-steel grade magnesium oxide product meeting enterprise-quality standard, and therefore, silicon-steel grade magnesium oxide market need further exploitation.

But the technical process of producing now silicon-steel grade magnesium oxide is longer, and purity is not high, unstable product quality, can not meet the requirement of the grain-oriented Si steel sheet production development of domestic quick growth, the method for producing silicon-steel grade magnesium oxide about salt lake magnesium resource is also less.

Summary of the invention

For the defect that the preparation technology of silicon-steel grade magnesium oxide in prior art exists, the object of the invention is to be to provide a kind of technique taking magnesium hydroxide as raw material and prepare regular appearance, silicon-steel grade magnesium oxide that purity is high, this technical process is short, obtained magnesium oxide steady quality, production efficiency is high, meets demand of industrial production.

The invention discloses a kind of by the magnesian technique of magnesium hydroxide preparation HIGH-PURITY SILICON grade of steel, this technique be first magnesium hydroxide is light-burned through 500 ~ 750 DEG C after, be added to the water, first be warmed up to 73 ~ 98 DEG C and carry out aquation, regulate temperature to 60 ~ 80 DEG C again, in water, slowly add ammonium bicarbonate soln carries out carbonization simultaneously, obtains suspension; By suspension filtered, filter gained filter residue after washing, drying, then be placed in 1050 ~ 1150 DEG C of temperature lower calcinations, obtain high-purity silicon-steel grade magnesium oxide.

Of the present inventionly also comprise following preferred version by the magnesian technique of magnesium hydroxide preparation HIGH-PURITY SILICON grade of steel:

Temperature light-burned in preferred scheme is 630 ~ 670 DEG C; Most preferably be 650 DEG C.

The temperature of calcining in preferred scheme is 1080 ~ 1120 DEG C; Most preferably be 1100 DEG C.

Time light-burned in preferred scheme is 0.5 ~ 2h.

In preferred scheme, calcination time is 1 ~ 2h.

In preferred scheme, the time of aquation is 0.5 ~ 2h.

The time of carbonization in preferred scheme is 2 ~ 4h.

In preferred scheme, the speed that adds of ammonium bicarbonate soln is 0.1 ~ 0.3L/h, and wherein, the concentration of ammonium bicarbonate soln is 0.5 ~ 0.8mol/L, and the add-on of bicarbonate of ammonia is 1 ~ 1.5 times of carburizing reagent theoretical molar amount.

Process light-burned in preferred scheme is: magnesium hydroxide is placed in stove, is warmed up to 500 ~ 700 DEG C carries out light-burned with the temperature rise rate of 5 ~ 10 DEG C/min.

The process of calcining in preferred scheme is: be placed in stove through washing, dried filter residue of crossing, be warmed up to 1050 ~ 1150 DEG C calcine with the temperature rise rate of 3 ~ 8 DEG C/min.

In preferred scheme, drying is dry 20 ~ 28h under temperature is the condition of 100 ~ 120 DEG C.

In preferred scheme, the light-burned product of magnesium hydroxide is added to the water by solid-to-liquid ratio 1g/15 ~ 25mL and carries out aquation.

Beneficial effect of the present invention: the silicon-steel grade magnesium oxide purity 1, prepared by present invention process is high, and purity reaches 98% ~ 99.5%, and magnesium oxide particle regular appearance, uniform particles; 2, technical process is short, and obtained magnesium oxide steady quality, production efficiency is high, meets demand of industrial production.

Accompanying drawing explanation

High-purity silicon-steel grade magnesium oxide SEM that [Fig. 1] obtains for embodiment 1 schemes; A is high magnification figure, b is low range figure;

The XRD analysis collection of illustrative plates of the carbonized product (presoma) that [Fig. 2] obtains for embodiment 1;

The magnesian XRD analysis collection of illustrative plates of HIGH-PURITY SILICON grade of steel that [Fig. 3] obtains for embodiment 1;

[Fig. 4] is for hydration temperature is on the impact of hydration efficiency;

The carbonized product presoma shape appearance figure that under [Fig. 5] differing temps, carbonization obtains;

[Fig. 6] is process flow diagram of the present invention.

Embodiment

Below in conjunction with embodiment, content of the present invention is further described, but the present invention is not only confined to following examples.

Embodiment 1

Magnesium hydroxide is put into retort furnace, and arranging temperature rise rate is 5 DEG C/min, is warming up to 650 DEG C, insulation 0.5h; Get the light-burned gained magnesium oxide of 10g, put into reactor, and add 200mL deionized water, be warming up to 80 DEG C fully to stir, after reaction 0.5h, reactor is cooled to 75 DEG C, now regulates bicarbonate of ammonia volume pump, in reactor, drip with the speed of 0.2L/h the ammonium bicarbonate soln that concentration is 50g/L, fully stir and react 3h; By gained suspension suction filtration, washing, at 100 DEG C, dry 24h, obtain presoma; Gained presoma is put into retort furnace, and arranging temperature rise rate is 5 DEG C/min, is warming up to 1100 DEG C, and insulation 1.5h, obtains high-purity silicon-steel grade magnesium oxide that purity is 99.5%.As shown in Figure 1, in Fig. 1, a can find out magnesium oxide product regular appearance to product shape appearance figure, and b can find out the even particle size of product.As can be seen from the XRD figure of intermediate product (presoma) (Fig. 2) and final product magnesium oxide (Fig. 3), product purity is high, and crystalline phase is single.

Embodiment 2

Magnesium hydroxide is put into retort furnace, and arranging temperature rise rate is 7 DEG C/min, is warming up to 550 DEG C, insulation 2h; Get the light-burned gained magnesium oxide of 10g, put into reactor, and add 250mL deionized water, be warming up to 85 DEG C and fully stir, reaction 1h; Afterwards, reactor is cooled to 60 DEG C, now regulates bicarbonate of ammonia volume pump, in reactor, drip with the speed of 0.2L/h the ammonium bicarbonate soln that concentration is 50g/L, fully stir and react 3h; By gained suspension suction filtration, washing, at 110 DEG C, dry 24h, obtain presoma; Gained presoma is put into retort furnace, and arranging temperature rise rate is 7 DEG C/min, is warming up to 1150 DEG C, and insulation 1h, obtains high-purity silicon-steel grade magnesium oxide that purity is 99.4%, magnesium oxide product regular appearance, even particle size.

Embodiment 3

Magnesium hydroxide is put into retort furnace, and arranging temperature rise rate is 9 DEG C/min, is warming up to 700 DEG C, insulation 1.5h; Get the light-burned gained magnesium oxide of 10g, put into reactor, and add 150mL deionized water, be warming up to 75 DEG C and fully stir, reaction 1h; Afterwards, reactor is cooled to 65 DEG C, now regulates bicarbonate of ammonia volume pump, in reactor, drip with the speed of 0.3L/h the ammonium bicarbonate soln that concentration is 50g/L, fully stir and react 2.5h; By gained suspension suction filtration, washing, at 110 DEG C, dry 20h, obtain presoma; Gained presoma is put into retort furnace, and arranging temperature rise rate is 4 DEG C/min, is warming up to 1050 DEG C, and insulation 1.5h, obtains high-purity silicon-steel grade magnesium oxide that purity is 99.4%, magnesium oxide product regular appearance, even particle size.

Embodiment 4

1, different hydration reaction temperature is examined or check on the impact of hydration efficiency.

Other experiment conditions are identical with documents 1, just regulated respectively by hydration temperature and test respectively at 60 DEG C, 75 DEG C, 90 DEG C.Experimental result as shown in Figure 4, illustrates to have good hydration reaction effect within the scope of the present invention 73 ~ 98 DEG C, poor lower than 73 DEG C of aquation effects.

2, the impact of different carbonization temperature on presoma pattern is examined or check.

Other experiment conditions are identical with documents 1, just carbonization temperature regulated respectively and test respectively at 70 DEG C, 80 DEG C, 90 DEG C.Experimental result as shown in Figure 5, it is the shape appearance figure of precursor product at 70 DEG C, 80 DEG C, 90 DEG C temperature that c, d, e are followed successively by, in figure c, product is slightly in elliposoidal, figure d product is regular spherical, in figure c, product pattern is poor, illustrate to have good carburizing reagent effect within the scope of the present invention 60 ~ 80 DEG C, carbonization temperature higher carbon effect is poor.

Claims

1. one kind by the magnesian technique of magnesium hydroxide preparation HIGH-PURITY SILICON grade of steel, it is characterized in that, after magnesium hydroxide is light-burned through 500 ~ 750 DEG C, be added to the water, first be warmed up to 73 ~ 98 DEG C and carry out aquation, regulate temperature to 60 ~ 80 DEG C again, in water, slowly add ammonium bicarbonate soln carries out carbonization simultaneously, obtains suspension; By suspension filtered, filter gained filter residue after washing, drying, then be placed in 1050 ~ 1150 DEG C of temperature lower calcinations, obtain high-purity silicon-steel grade magnesium oxide.

2. technique as claimed in claim 1, it is characterized in that, light-burned temperature is 630 ~ 670 DEG C.

3. technique as claimed in claim 1, it is characterized in that, the temperature of calcining is 1080 ~ 1120 DEG C.

4. the technique as described in any one of claims 1 to 3, is characterized in that, the light-burned time is 0.5 ~ 2h; Calcination time is 1 ~ 2h.

5. technique as claimed in claim 1, it is characterized in that, the time of aquation is 0.5 ~ 2h; The time of carbonization is 2 ~ 4h.

6. technique as claimed in claim 1, it is characterized in that, the speed that adds of ammonium bicarbonate soln is 0.1 ~ 0.3L/h, and wherein, the concentration of ammonium bicarbonate soln is 0.5 ~ 0.8mol/L, and the add-on of bicarbonate of ammonia is 1 ~ 1.5 times of carburizing reagent theoretical molar amount.

7. technique as claimed in claim 1, it is characterized in that, light-burned process is: magnesium hydroxide is placed in stove, is warmed up to 500 ~ 700 DEG C carries out light-burned with the temperature rise rate of 5 ~ 10 DEG C/min.

8. technique as claimed in claim 1, it is characterized in that, the process of calcining is: be placed in stove through washing, dried filter residue of crossing, be warmed up to 1050 ~ 1150 DEG C calcine with the temperature rise rate of 3 ~ 8 DEG C/min.

9. technique as claimed in claim 1, is characterized in that, described drying is dry 20 ~ 28h under temperature is the condition of 100 ~ 120 DEG C.

10. technique as claimed in claim 1, is characterized in that, the light-burned product of magnesium hydroxide is added to the water by solid-to-liquid ratio 1g/15 ~ 25mL and carries out aquation.