Method for preparing high-purity calcium aluminate by using rotary kiln

A calcium aluminate and rotary kiln technology, which is applied to the preparation of calcium aluminate, alkaline earth metal aluminate/alumina/hydroxide, etc., can solve problems such as troublesome operation, insufficient sintering, and low production efficiency, and achieve simplification Effects of production steps, shortening of production time, and increase of production efficiency

Inactive Publication Date: 2018-06-01
浙江海翔净水科技股份有限公司 +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This method is insufficient for sintering, and there is still a large amount of unsintered raw material to become calcium aluminate, which requires repeated sintering, troublesome operation, low production efficiency, and large waste of materials
[0005] There is also a semi-wet method for preparing calcium aluminate, which is to mix aluminum-containing compounds with calcium carbonate, and then stir while pouring water until they are mixed into a paste, and then calcined. The calcining temperature is 1200°C. When stirring, the steps are cumbersome. After mixing into a paste and sintering, it will form larger lumps, which are not easy to break, and the temperature is too low, and the soluble aluminum content after sintering is too low.

Method used

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  • Method for preparing high-purity calcium aluminate by using rotary kiln
  • Method for preparing high-purity calcium aluminate by using rotary kiln

Examples

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preparation example Construction

[0043] Please refer to figure 2 , The prepared high-purity calcium aluminate can be directly reacted with hydrochloric acid to prepare polyaluminum chloride, and the preparation method includes the following steps:

[0044] Step S7: adding 31-58 parts by weight of hydrochloric acid into the atmospheric reaction tank, adding 25-55 parts by weight of water and stirring;

[0045] Step S8: Add 15-18 parts by weight of high-purity calcium aluminate slowly into the atmospheric reaction tank, and control the feeding time within 20-30 minutes;

[0046] Step S9: React at a temperature of 90-110°C for 1-3 hours, and obtain a finished product after pressure filtration or precipitation.

[0047] Among them, in the hydrochloric acid used, the content of hydrogen chloride HCl is ≥31%.

Embodiment 1

[0049] In the first embodiment of the method for preparing high-purity calcium aluminate using a rotary kiln in the embodiment of the present invention:

[0050] Step (1): mixing industrial calcium oxide and industrial alumina according to the molar ratio of Ca and Al of 1:1.5 to obtain raw meal.

[0051] Step (2): Add coal powder to the raw meal and mix uniformly, wherein the coal powder accounts for 10% of the total amount of the raw meal.

[0052] Step (3): Send the mixture into a rotary kiln for sintering at 1380°C for 1 hour, and cool to obtain clinker.

[0053] Step (4): Grind the clinker through a ball mill for 0.5 hours.

[0054] Step (5): screening through a screening device, and the obtained powdery particles are high-purity calcium aluminate.

[0055] Step (6): the obtained large particles or massive particles are returned to the ball mill for ball milling until they become powdery particles.

[0056] Preferably, the CaO content in the industrial calcium oxide is not less than ...

Embodiment 2

[0062] In the second embodiment of the method for preparing high-purity calcium aluminate by using a rotary kiln in the embodiment of the present invention:

[0063] Step (1): mixing industrial calcium carbonate and aluminum hydroxide according to the molar ratio of Ca and Al of 1:4 to obtain raw meal.

[0064] Step (2): Add coal powder to the raw meal and mix evenly, wherein the coal powder accounts for 25% of the total amount of the raw meal.

[0065] Step (3): Send the mixture into a rotary kiln for sintering at 1500°C for 1 hour, and cool to obtain clinker.

[0066] Step (4): Grind the clinker through a ball mill for 1.5 hours.

[0067] Step (5): screening through a screening device, and the obtained powdery particles are high-purity calcium aluminate.

[0068] Step (6): the obtained large particles or massive particles are returned to the ball mill for ball milling until they become powdery particles.

[0069] Preferably, the CaO content in industrial calcium carbonate is 55%-56%.

[...

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Abstract

The invention discloses a method for preparing high-purity calcium aluminate by using a rotary kiln. The method comprises the following steps: uniformly mixing a calcium-containing compound and an aluminum-containing compound according to a molar ratio of elemental Ca to elemental Al of (1: 1.5) to (1: 4) to obtain a raw material; adding pulverized coal into the raw material, and uniformly mixing;sending a mixture into the rotary kiln, sintering at 1350-1500 DEG C for 0.5-1 hour, and cooling to obtain a clinker; milling and pressing the clinker for 0.5-1.5 hours by using a ball mill; and screening by using a screening device to obtain powdery granules, namely the high-purity calcium aluminate. By the method, the steps are simple, operation is easy, the production steps are simplified, theproduction time is shortened, the production efficiency is improved, and industrial production can be achieved.

Description

Technical field [0001] The invention relates to a method for preparing industrial raw materials, in particular to a method for preparing high-purity calcium aluminate by using a rotary kiln. Background technique [0002] Calcium aluminate is one of the main raw materials for the production of polyaluminum chloride. The current conventional industrial production of calcium aluminate uses bauxite or waste aluminum slag and limestone as the main raw materials. Because the raw materials of bauxite, waste aluminum slag and limestone contain a large amount of metal impurities, calcium aluminate can only be used for The polyaluminum chloride is used for adjusting the alkalinity, and the color of the prepared polyaluminum chloride is light yellow to yellowish brown liquid, the content of heavy metals is high, the purity of the product is not high, and the content of alumina is low. [0003] With the continuous development of the national economy, the index requirements for polyaluminum ch...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01F7/16
CPCC01F7/164C01P2004/61
Inventor 沈烈翔沈萍邓木跃文荐鸣
Owner 浙江海翔净水科技股份有限公司
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