Method for using aluminum ash as fuel, correction material and sintering aid for dry cement production

Abstract

A method for using aluminum ash as fuel, correction material and sintering aid for dry-process cement production comprises the following steps: mixing aluminum ash and a catalytic combustion accelerant in a conveying pipeline or a combustor, spraying the mixture into a kiln tail decomposing furnace and / or a kiln head rotary kiln of a dry-process cement production line through an injection pipe or the combustor, under the catalytic activation action of a catalytic combustion accelerant, the raw materials are quickly burnt out in a high-temperature environment and under a suspension condition, heat energy generated by combustion is directly supplied to decomposition of calcium carbonate and / or sintering of clinker, and activated aluminum oxide generated by combustion is directly used as an aluminum correction raw material of a raw material; halides contained in the aluminum ash, other raw materials and catalytic elements after acting directly form a sintering aid for raw material calcination and / or clinker calcination. By utilizing the method, the aluminum ash can be effectively and comprehensively utilized, so that the cost for producing original combustion materials from cement can be reduced, and hazardous wastes can be co-processed by utilizing a cement kiln to protect the ecological environment; the method is simple and convenient to operate, easy to implement and low in investment, and various aluminum ashes can be consumed in a large-scale manner.

Description

technical field [0001] The invention relates to a harmless, resourceful and energy-based comprehensive utilization method of industrial waste slag aluminum ash, in particular to a method for using aluminum ash as fuel, correction material and sintering aid for dry-process cement production. Background technique [0002] Aluminum ash mainly comes from the process of aluminum ingot casting in electrolytic aluminum enterprises, aluminum processing and casting in aluminum profile enterprises, and remelting of scraps in recycled aluminum enterprises. [0003] In 2020, the output of primary aluminum (electrolytic aluminum) in my country is 37.08 million tons, an increase of 5.6% compared with the production capacity in 2019. About 110 kg of aluminum ash is produced for every 1 t of aluminum produced, so the emission of aluminum ash is also increasing. According to reports, my country produced nearly 3.5 million tons of aluminum ash in 2019, with an annual growth rate of nearly 2%....

AI Technical Summary

Problems solved by technology

The technological process of this method is relatively complicated, and the extraction efficiency is not high because the aluminum ash contains more impurities.

[0012] (2) As converter and molten iron desulfurizer: secondary aluminum ash contains a large amount of Al 2 o 3 , a certain amount of limestone can be added as a new desulfurizer for industrial boilers, but the amount of use is limited due to the high amount of harmful substances in the secondary aluminum ash

[0013] (3) Used as a refining agent for steelmaking: use aluminum ash to prepare calcium aluminate refining agent, which is used to remove harmful element sulfur in high-quality steel, but the process is complicated and energy consumption is high, and large-scale application has not yet been realized

[0014] (4) Preparation of aluminum sulfate: Aluminum ash is reacted with sulfuric acid to prepare aluminum sulfate. The disadvantage is that the added value of aluminum sulfate produced is low, and harmful gas will be generated during the preparation process, causing secondary pollution to the environment

[0015] (5) Preparation of polyaluminum sulfate: first prepare aluminum sulfate, then add a variety of polymerization agents for polymerization to prepare polyaluminum sulfate as a flocculant, but the process is relatively cumbersome

In addition, due to the recent sharp rise in thermal coal prices, many industrial enterprises have experienced power cuts or shutdowns. Therefore, cement companies are also deploying some relatively cheap bituminous coal, high-sulfur coal, and anthracite coal with low calorific value to reduce production costs. This will easily reduce the combustion speed and flame temperature of pulverized coal, which will have a great impact on the stable operation of the kiln system, and at the same time affect the output and quality of clinker firing

[0019] However, aluminum ash contains some metal aluminum with high calorific value, and aluminum nitride has not been effectively utilized (the calorific value of metal aluminum is 30222.22kJ / kg, and the heat of formation of aluminum nitride is about 10111kcal / kg), especially in primary aluminum ash. The metal aluminum content can reach 15%~70%. At present, most of the disposal methods are used to extract aluminum. The metal aluminum content in the secondary aluminum ash after aluminum extraction is still 8%~20%. Secondly, due to the Hazardous waste characteristics, the alumina in primary aluminum ash and secondary aluminum ash has not been fully and effectively utilized