Method for preparing high-strength sulfate aluminum cement co-production sulfuric acid through calcining by steps

A technology of sulfoaluminate cement and staged calcination, which is applied in the direction of sulfur trioxide/sulfuric acid, etc., can solve the problems of complicated equipment and technological process, high production cost, and increased cost and difficulty of preparing sulfuric acid from sulfur dioxide.

Active Publication Date: 2017-05-10
KINGENTA ECOLOGICAL ENG GRP +1
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Problems solved by technology

[0003] Chinese patent document CN100351197C discloses a manufacturing process of rapid-hardening sulfoaluminate cement. The raw material proportion of this process is 17-20% of dehydrated phosphogypsum, 45-52% of limestone, and 31-35% of bauxite. The successful use of waste phosphogypsum to replace the natural gypsum in the raw meal mix can partially reduce the cost of sulphoaluminate cement, but the amount of phosphogypsum used in this process only accounts for 17-20% of the raw meal mix, In the invention, 45-52% limestone is needed, which fails to achieve the purpose of effectively utilizing phosphogypsum. In addition, the decomposition of phosphogypsum in the process will release sulfur dioxide, which will cause environmental pollution if not handled properly
[0004] Chinese patent document CN103304170B discloses a method for producing sulphoaluminate cement. Limestone, phosphogypsum, low-grade bauxite and coke are prepared in a certain proportion to make cement raw meal, which is calcined at high temperature after grinding and mixing. In the process, by promoting the decomposition of phosphogypsum as much as possible, the calcium oxide generated by the decomposition replaces part of the limestone, and the sulfur dioxide gas can be collected to prepare sulfuric acid. The ra

Method used

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  • Method for preparing high-strength sulfate aluminum cement co-production sulfuric acid through calcining by steps
  • Method for preparing high-strength sulfate aluminum cement co-production sulfuric acid through calcining by steps

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preparation example Construction

[0012] a. Preparation of cement raw meal:

[0013] Dosing according to the following mass parts: 75-90 parts of phosphogypsum, 19-28 parts of bauxite, 1-2 parts of steel slag, 1-3 parts of silica, 3-4 parts of anthracite; mix and grind each component, Cement raw meal obtained after homogenization;

[0014] b. Preparation of cement clinker:

[0015] The cement raw meal prepared in step a is calcined in stages to obtain cement clinker, and the sulfur dioxide tail gas generated in the calcining process is collected and sent to a sulfuric acid preparation system to prepare sulfuric acid;

[0016] c. Preparation of sulphoaluminate cement:

[0017] The cement clinker obtained in step b is ground again to obtain sulphoaluminate cement.

[0018] Preferred of the present invention:

[0019] The fineness of the material after grinding in step a is 80-150 mesh;

[0020] Al in the bauxite 2 o 3 The mass fraction is 60-75%, more preferably 66%;

[0021] The phosphogypsum is hemihyd...

specific Embodiment approach

[0059] In order to better understand the essence of the present invention, the content of the present invention will be further described below in conjunction with the examples, but it cannot be regarded as a limitation of the present invention.

[0060] The phosphogypsum in each embodiment is all taken from the hemihydrate phosphogypsum by-produced by the new wet-process phosphoric acid of Jinzheng Da Nuo Taier Chemical Co., Ltd., its main components are shown in Table 1, and the main components of steel slag are shown in Table 2, Bauxite is produced in Shijiazhuang, Hebei, and its main components are shown in Table 3, and the main components of silica are shown in Table 4 below.

[0061] Table 1: Main components and contents of phosphogypsum

[0062] components CaO SO 3

Fe 2 o 3

Al 2 o 3

SiO 2

content% 31.26 44.63 0.12 0.49 2.32

[0063] Table 2: Main components and content of steel slag

[0064] components Ca...

Embodiment 1

[0070] Dosing according to the following parts by mass: 75 parts of phosphogypsum, 28 parts of bauxite, 1 part of steel slag, 3 parts of silica, and 3 parts of anthracite; mix the components evenly, grind them to a fineness of 80 mesh, and homogenize Make a block of 250*100*50mm to obtain cement raw meal; place the prepared block raw meal in a tunnel kiln for calcination, first raise the temperature to 900°C, and calcine at this temperature for 40 minutes, then raise the temperature to 1300°C, Calcined at this temperature for 20 minutes, cooled to obtain cement clinker, after calcined, the tail gas containing sulfur dioxide was sent to the sulfuric acid preparation system to prepare sulfuric acid; the calcined clinker was ground again to 350m2 / Kg, and the sulphoaluminate cement product could be obtained. The mechanical properties of the obtained sulfoaluminate cement are shown in Table 5.

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Abstract

The invention relates to a method for preparing high-strength sulfate aluminum cement co-production sulfuric acid through calcining by steps. The method comprises the following steps: completely replacing limestone and natural gypsum by ardealite, grinding and homogenizing bauxite, slag, silica and anthracite, and preparing the sulfate aluminum cement through calcining by steps. The ardealite utilization rate is greatly improved, and sulfuric acid can be prepared by absorbing high-concentration sulfur dioxide tail gas. The sulphoaluminate cement clinker prepared by the method disclosed by the invention is high in hardening rate, high in early strength and enhanced and stable in long-term strength. The performance test proves that the mechanical strength of the prepared sulfate aluminum cement meets the rapid hardening sulfate aluminum cement standard.

Description

technical field [0001] The invention relates to a method for preparing high-strength sulphoaluminate cement with co-production of sulfuric acid by segmental calcination, which belongs to the technical field of cement preparation. Background technique [0002] With the modernization of engineering technology, the technical requirements for special cement are getting higher and higher. These include the special requirements for the speed of rapid setting and hardening and the hardness of each stage during the construction of special projects, such as the connection construction of cement pipelines, and the construction of foundation sites for large-scale equipment. Although the application and sales market are constantly expanding, they are limited due to the high cost of products, making more users out of reach. On the other hand, as one of the world's three major phosphate fertilizer producers, it is difficult to realize mass utilization due to the restriction of phosphogyp...

Claims

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Application Information

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IPC IPC(8): C04B7/32C01B17/69
CPCC01B17/69C04B7/323
Inventor 宋国发胡兆平郑磊刘阳
Owner KINGENTA ECOLOGICAL ENG GRP
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