A kind of treatment method of dry desulfurization ash

Abstract

The invention provides a treatment method for dry desulfurization ash, comprising the following steps: a) bringing oxidized hot air and dry desulfurized ash to be treated together into an oxidation device for contact, to obtain oxidized high-temperature desulfurized ash and oxidized hot air respectively; The oxygen content of the oxidation hot air is 15%-22%, and the temperature is 400°C-900°C; b) cooling the oxidized high-temperature desulfurization ash obtained in step a) to obtain a processed product. Compared with the prior art, the treatment method provided by the present invention uses oxidation hot air and dry desulfurization ash to directly and fully contact oxidation, has high heat transfer and mass transfer efficiency, shortens the oxidation time, and has a wider temperature range and is suitable for oxygen-containing The volume requirements are wider, and the hot air after oxidation is sent to the hot air recycling device for continued use, so it has better adaptability, operability and economy, and the processed product is suitable for further application as a cement retarder.

Description

technical field [0001] The invention relates to the technical field of resource utilization of dry desulfurization ash, and more specifically relates to a treatment method for dry desulfurization ash. Background technique [0002] At present, my country's flue gas desulfurization mainly adopts wet, semi-dry and dry desulfurization processes. As my country's air quality requirements become more and more stringent, SO 3 And chimney "white dragon" and desulfurization wastewater put forward treatment requirements. More and more industrial flue gas purification devices include circulating fluidized bed (CFB), rotary spray drying (SDA), dry absorbent injection desulfurization (DSI) and other dry Method / semi-dry desulfurization device. The resulting dry desulfurization ash is also increasing. In 2018, the national dry desulfurization ash is estimated to exceed 15 million tons, and it is expected to exceed 25 million tons per year after 2020. [0003] Dry desulfurization ash speci...

AI Technical Summary

Problems solved by technology

Although dry desulfurization ash contains a large amount of calcium sulfite similar to calcium sulfate in desulfurized gypsum, it has been found through research that there are two problems in using dry desulfurization ash containing calcium sulfite directly as a cement retarder: one is to partially The retarding time of clinker is too long; second, the adaptability to different clinkers is poor

However, the above-mentioned technical solution has the following defects: First, the patents with application numbers 201410380659.4 and 201020627340.4 use an external heating furnace to generate high-temperature hot flue gas, which requires burning a large amount of fuel and high energy consumption. Under the current environmental protection situation, the external heating furnace can only be used Natural gas or coal gas is used as fuel, and the fuel cost is high, which will inevitably lead to high cost of dry desulfurization ash oxidation

Although the patent with application number 201410380382.5 uses high-temperature flue gas at 600-800°C generated by power generation boilers or sintering machines, these high-temperature flue gases are used for power generation or reuse in the main process of power generation boilers and sintering machines. , which is used to heat the heating section of the rotary oxidation kiln, will inevitably bring about the heat loss of these high-temperature flue gases, so that the temperature of the cited high-temperature flue gas will drop significantly, affecting the main process of the power generation boiler and sintering machine, and the possibility of actual adoption is not large; Secondly, the above-mentioned patent requires that the atmosphere in the kiln must ensure that the oxygen content reaches 20-25%, so this technology must add additional oxygen supply equipment, which will greatly increase the cost on the one hand, and increase the difficulty of control on the other hand; thirdly, the dry method in the rotary kiln The desulfurization ash and gas are in a relatively separated state, and the contact is insufficient. The oxidation speed of the dry desulfurization ash is slow, and it needs to stay in the rotary kiln for a long time. Pass, the heating heat source is outside the kiln, so the outer wall is heated unevenly, local high temperature inevitably occurs in the oxidation section, and hardening is easy to occur

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