CN103073264A

CN103073264A - Method for preparing ceramsite by utilizing high-moisture-content sludge

Info

Publication number: CN103073264A
Application number: CN2013100561798A
Authority: CN
Inventors: 赵明银; 赵誉; 王新朝
Original assignee: HENAN ENVIRONMENTAL PROTECTION TECHNOLOGY Co Ltd
Current assignee: HENAN ENVIRONMENTAL PROTECTION TECHNOLOGY Co Ltd
Priority date: 2013-02-07
Filing date: 2013-02-22
Publication date: 2013-05-01

Abstract

The invention relates to a method for preparing ceramsite by utilizing high-moisture-content sludge, which belongs to the technical field of the environment and relates to the resource-oriented utilization of solid waste. The method comprises the following steps of (1) adjusting the moisture content of the sludge to 90 to 99.6 percent, adding ingredients, and uniformly stirring the ingredients and the sludge; and (2) dehydrating and drying the uniformly-stirred mixed slurry to obtain mixed mud cakes, and granulating, molding and sintering the mixed mud cakes at high temperature to obtain a ceramsite finished product. The municipal sludge with the moisture content of 90 to 99.6 percent is used as the primary raw material, the mobility of the sludge is good, and the raw materials can be uniformly mixed through simple stirring after ingredients are charged into the sludge. The mixing uniformity of the raw materials is greatly improved, so that the rate of sintering finished products of the ceramsite also can be increased and reach more than 95 percent. Meanwhile, compared with the traditional dry-method ceramsite production method, the energy consumption is low, drying and pulverizing equipment can be saved, high economic benefit can be achieved, and a way can be found for the treatment of the municipal sludge.

Description

A kind of method of utilizing high water-containing sludge to prepare haydite

Technical field

The invention belongs to the environmental technology field, relate to the recycling of solid waste, relate in particular to a kind of method of utilizing high water-containing sludge to prepare haydite.

Background technology

Municipal sludge, mainly refer to the fittings after the sewage disposal, be a kind of extremely complicated non-average body that is comprised of organic relic, bacterium thalline, inorganic particle, colloid etc., it becomes branch because of the factors such as the level of economic development, living habit and seasonal variation generation variation in various degree.Along with the acceleration of Urbanization in China, treatment rate of domestic sewage improves year by year, and the sludge discharge that sewage work produces grows with each passing day.Its water ratio of mud of discharging from the sewage work gravity settling basin is more than 90%, must be through could qualified discharge after the mechanical dehydration.Clear among the GJ3025-1993 " municipal sewage plant's sewage sludge emission standard ": the sludge from wastewater treatment plant in factory after stabilizing treatment should carry out processed, and its water ratio should be less than 80%.In recent years, consider that mud still easily grows microorganism under this humidity, have this standard is brought up to trend below 60% (referring to " municipal sewage sludge is processed disposal technology standard (exposure draft) ").Yet, even if water ratio at the municipal sludge below 60%, wherein also contains the hazardous and noxious substances such as a lot of heavy metals, organism, as only disposing the secondary pollution that very easily causes the soil with plain modes such as landfill, compost.Therefore how innoxious, minimizing, disposal of resources municipal sludge have become one of important process of environmental protection industry (epi) and even governments at all levels.

There are some researches show, main component and the one of clay raw materials of municipal sludge are more approaching, make haydite take it as major ingredient and can realize the minimizing of cities and towns solid waste, innoxious and resource utilization, beyond doubt present best processing mode.Utilize municipal sludge to make haydite, mainly contain at present two kinds of techniques: (1) wet method potting should be at first with sludge drying to water ratio below 60%, and add a certain amount of auxiliary material and additive, mix rear sintering (referring to " municipal sewage sludge is processed disposal technology standard (exposure draft) " the 14.3rd joint, potting grain).Also there is the document record to use water ratio to carry out the wet method potting as the mud of 75%-85%.But water ratio is lower than 85% mud and has been semi-solid state shape (Fig. 1 is that water ratio is 85% mud photo), already lost flowability.Simultaneously, owing to also containing the impurity such as a large amount of hairs, floss in the mud, add in this state batching, stirring is got up very difficult, is difficult to make them to mix by mechanical force.Raw material mixes the uneven sintering finished rate that can directly affect haydite, and the haydite after firing is easy to crack and easily form cavity, causes its hardness, outward appearance not to reach requirement.In addition, because the raw material water ratio is higher, just need repeatedly oven dry when firing, the production cycle is elongated thereupon.On the other hand, water ratio is stronger in the mud stickiness of 60%-85%, and agitation mixer is had relatively high expectations (such as wanting increasing power), has directly increased production cost.(2) the dry method potting will be dried into from the municipal sludge that sewage work discharges over dry mud first, pulverize, will grind to form less than 200 purpose powder, add water modulation, moulding behind mixing, will fire with other batching.During the dry method potting, raw material mixes under pulverulence, mixes easily much than wet method although operate, but still is difficult to realize thorough mixing.Prior thing, raw material need to experience twice oven dry and a pulverization process, need to strengthen equipment investment, and this can increase production cost undoubtedly.

Summary of the invention

Based on the existing variety of problems of prior art, the invention provides a kind of method of utilizing high water-containing sludge to prepare haydite.

For reaching above-mentioned purpose, the present invention has taked following technical scheme: a kind of method of utilizing high water-containing sludge to prepare haydite may further comprise the steps: 1) moisture percentage in sewage sludge is adjusted to 90-99.6%, adds batching, stir; 2) with the mixing mud dehydration and drying that stirs, get the mixing mud cake, carry out granulating and forming, high temperature sintering to mixing mud cake, namely get the haydite finished product.

By weight, the required batching of 20-40 part over dry mud is: iron protochloride 3-8 part, flyash 30-50 part, magnesium chloride 3-8 part, above carbide slag or lime 2-5 part, waste steel slag or the bauxitic clay 10-20 part of 200 orders.

Described step 2) in, the water ratio that dehydration and drying will mix mud cake is reduced to 20 ~ 60%.

Described step 2) in, utilizes the high pressure sheet frame that mixing mud is carried out filter-press dehydration, then deliver to the mummification of drying sludge canopy.

The moisture percentage in sewage sludge of discharging from the sewage work gravity settling basin is fluid state at 90-99.6%, has good flowability, can directly utilize.For the mud in other sources, if water ratio is low, poor fluidity, can improve its water ratio by adding water, satisfy after the water content requirement of 90-99.6% also applicable method of the present invention.Fig. 2 is that water ratio is 90% mud photo, and in fact, when moisture percentage in sewage sludge changed between 90-99.6%, its apparent condition seemed all relatively to approach.The present invention adds inside batching and by simple agitation each raw material mixed afterwards take it as initial feed.The water ratio that dehydration and drying will mix mud cake is reduced to 20 ~ 60%, has both helped moulding, has reduced again and has fired difficulty (water ratio is too high, and firing time length and haydite easily burst).In the batching, iron protochloride, magnesium chloride can promote moisture to separate out from mud; Flyash, carbide slag or lime can be played a supporting role when press filtration, help carrying out smoothly of press filtration; In addition, flyash is still constructed the important component of haydite skeleton, can promote the support strength of haydite.

Among the present invention, because the mixing uniformity of raw material significantly promotes, yield rate also improves thereupon, more than 95%.Simultaneously, compare with traditional dry method potting, energy consumption of the present invention is low, has saved oven dry, disintegrating apparatus, has higher economic benefit, has really found outlet for the processing of municipal sludge.

Description of drawings

Fig. 1 is that water ratio is 85% mud photo;

Fig. 2 is that water ratio is 90% mud photo.

Embodiment

The present invention will be further described below in conjunction with specific embodiment.

Embodiment 1

A kind of method of utilizing high water-containing sludge to prepare haydite may further comprise the steps:

1) moisture percentage in sewage sludge is adjusted to 90%, adds batching, stir; By weight, the raw material of preparation haydite consists of: 40 parts in over dry mud, 3 parts of iron protochlorides, 35 parts in flyash, 8 parts in magnesium chloride, 5 parts of carbide slags (crossing 200 mesh sieves), 20 parts of waste steel slags.

2) utilize the high pressure sheet frame that the mixing mud that stirs is carried out filter-press dehydration, then deliver to the mummification of drying sludge canopy; When water ratio reaches 60%, stop mummification and must mix mud cake; Carry out granulating and forming, high temperature sintering to mixing mud cake, namely get the haydite finished product.Yield rate is 95%.

Embodiment 2

1) moisture percentage in sewage sludge is adjusted to 95%, adds batching, stir; By weight, the raw material of preparation haydite consists of: 30 parts in over dry mud, 5 parts of iron protochlorides, 50 parts in flyash, 3 parts in magnesium chloride, 2 parts in lime (crossing 240 mesh sieves), 18 parts of waste steel slags.

2) utilize the high pressure sheet frame that the mixing mud that stirs is carried out filter-press dehydration, then deliver to the mummification of drying sludge canopy; When water ratio reaches 60%, stop mummification and must mix mud cake; Carry out granulating and forming, high temperature sintering to mixing mud cake, namely get the haydite finished product.Yield rate is 98%.

Embodiment 3

1) moisture percentage in sewage sludge is adjusted to 99.6%, adds batching, stir; By weight, the raw material of preparation haydite consists of: 20 parts in over dry mud, 8 parts of iron protochlorides, 30 parts in flyash, 5 parts in magnesium chloride, 3 parts of carbide slags (crossing 300 mesh sieves), 10 parts of bauxitic clays.

2) utilize the high pressure sheet frame that the mixing mud that stirs is carried out filter-press dehydration, then deliver to the mummification of drying sludge canopy; When water ratio reaches 60%, stop mummification and must mix mud cake; Carry out granulating and forming, high temperature sintering to mixing mud cake, namely get the haydite finished product.Yield rate is 96%.

Claims

1. a method of utilizing high water-containing sludge to prepare haydite is characterized in that, may further comprise the steps: 1) moisture percentage in sewage sludge is adjusted to 90-99.6%, adds batching, stir; 2) with the mixing mud dehydration and drying that stirs, get the mixing mud cake, carry out granulating and forming, high temperature sintering to mixing mud cake, namely get the haydite finished product.

2. utilize as claimed in claim 1 high water-containing sludge to prepare the method for haydite, it is characterized in that, by weight, the required batching of 20-40 part over dry mud is: iron protochloride 3-8 part, flyash 30-50 part, magnesium chloride 3-8 part, above carbide slag or lime 2-5 part, waste steel slag or the bauxitic clay 10-20 part of 200 orders.

3. utilize as claimed in claim 1 or 2 high water-containing sludge to prepare the method for haydite, it is characterized in that described step 2) in, the water ratio that dehydration and drying will mix mud cake is reduced to 20 ~ 60%.

4. utilize as claimed in claim 3 high water-containing sludge to prepare the method for haydite, it is characterized in that step 2) in, utilize the high pressure sheet frame that mixing mud is carried out filter-press dehydration, then deliver to the mummification of drying sludge canopy.