Method for preparing gypsum powder composition

Abstract

The invention provides a method for preparing a gypsum powder composition. The method comprises the following steps: step 100, preparing potassium gypsum; step 200, mixing the potassium gypsum prepared in the step 100 with anhydrous gypsum; and step 300, adding water into the mixture obtained in the step 200, stirring, and standing for 24 hours. The preparation method disclosed by the invention combines a chemical preparation and a mechanical method, and can improve the hydration rate of the anhydrite.

Description

Technical Field

[0001] The present invention relates to the field of gypsum, and particularly to a method for preparing a gypsum powder composition. Background Art

[0002] Gypsum building materials, such as gypsum powder or gypsum board, usually use dihydrate gypsum as raw material. This is because dihydrate gypsum has chemical activity.

[0003] Anhydrite, also known as anhydrous gypsum, mainly consists of anhydrous calcium sulfate, which is generally produced naturally. It is also a by-product of the phosphate industry and some other industries. Anhydrite has low reactivity and cannot be directly used to produce gypsum building products. It is necessary to convert anhydrite into dihydrate gypsum. Currently, chemical agents or physical methods are usually used to convert anhydrite into dihydrate gypsum. However, the conversion rate of the current methods is not high. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for converting anhydrite into dihydrate gypsum.

[0005] To this end, the present invention provides a method for preparing a gypsum powder composition, comprising the following steps:

[0006] Step 100, preparing potassium gypsum;

[0007] Step 200, mixing the potassium gypsum prepared in step 100 with anhydrite; and

[0008] Step 300, adding water to the mixture obtained in step 200, stirring, and standing for 24 hours.

[0009] Among them, step 100 includes:

[0010] Step 110, mixing dihydrate gypsum and potassium gypsum in a weight ratio of 1:1;

[0011] Step 120, performing ball milling on the mixture obtained in step 110, with a ball-to-powder ratio of 1:1, a ball milling time of 30 minutes, and a ball milling speed of 300 revolutions per minute.

[0012] Among them, in step 200, the weight of potassium gypsum does not exceed 5% of the weight of anhydrite.

[0013] Among them, in step 300, the weight ratio of the mixture to water is 1:0.5 - 0.7.

[0014] The preparation method of the present invention combines chemical agents and mechanical methods, and can improve the hydration rate of anhydrite. Detailed Embodiments

[0015] The following describes specific embodiments of the present invention.

[0016] According to the present invention, first, potassium gypsum is prepared using gypsum dihydrate and potassium sulfate.

[0017] Desulfurized gypsum can be used as the material for gypsum dihydrate. The desulfurized gypsum and potassium sulfate are mixed evenly according to a weight ratio of 1:1. The resulting mixture is put into a ball mill for ball milling treatment. The ball mill can be obtained through commercial channels.

[0018] In the ball milling treatment, the ball-powder ratio is 1:1. The ball milling speed is set at 300 revolutions per minute, and the ball milling time is set at 30 minutes.

[0019] Potassium gypsum is obtained after the ball milling treatment and is in powder form.

[0020] Secondly, the obtained potassium gypsum powder is mixed with anhydrous gypsum powder. The weight of potassium gypsum does not exceed 5% of the weight of anhydrous gypsum.

[0021] Thirdly, the powdery mixture of potassium gypsum and anhydrous gypsum is stirred with water to form a slurry. Among them, the amount of water used is 50wt.% - 70wt.% of the powdery mixture.

[0022] The mixed slurry is placed at room temperature for 24 hours.

[0023] After that, the loss of crystal water of the obtained slurry can be measured to determine the hydration rate of anhydrous gypsum.

[0024] Table 1 gives examples of different dosages of potassium gypsum and the results of the detection of crystal water loss. Among them, the control example is the natural hydration rate of anhydrous gypsum.

[0025] Table 1

[0026] Control Example Example 1 Example 2 Example 3 Example 3 Example 3 Example 3 Amount of potassium gypsum added 0 0.50％ 1.00％ 1.50％ 2.00％ 3.50％ 5.00％ Hydration rate after 24 hours 13.30％ 19.95％ 20.70％ 20.10％ 22.21％ 25.99％ 28.11％

[0027] It can be seen that when the dosage of potassium gypsum increases, the 24-hour hydration rate of anhydrous gypsum also increases.

[0028] In the above description, the details of the technical solution of the present invention are elaborated. However, those skilled in the art can understand that the present invention is not limited to the specific details listed in the above embodiments, but can vary within the scope defined by the claims.

Claims

1. A method for preparing a gypsum powder composition, comprising the following steps: Step 100, preparing potassium gypsum; Step 200, mixing the potassium gypsum prepared in Step 100 with anhydrous gypsum; and Step 300, adding water to the mixture obtained in Step 200, stirring, and leaving it for 24 hours.

2. The method for preparing a gypsum powder composition according to claim 1, wherein, Step 100: Step 110, mix gypsum dihydrate and syngenite in a weight ratio of 1:1; Step 120, perform ball milling on the mixture obtained in Step 110.

3. The method for preparing a gypsum powder composition according to claim 2, wherein, In the ball milling treatment described in Step 120, the ball-powder ratio is 1:1, the ball milling time is 30 minutes, and the ball milling speed is 300 revolutions per minute.

4. The method for preparing a gypsum powder composition according to claim 1, wherein, In Step 200, the weight of syngenite does not exceed 5% of the weight of anhydrite.

5. The method for preparing a gypsum powder composition according to claim 1, wherein, In Step 300, the weight ratio of the mixture to water is 1:0.5 - 0.7.