CN102850077A - Method for producing sludge-based ecological concrete product - Google Patents

Abstract

The invention discloses a production method of sludge-based ecological concrete products. It is made of 2~20% of sludge, 10~25% of fine sand, 40~55% of coarse aggregate, 15~25% of cement, 0.5~10% of water, and 0.5~2% of water reducing agent. Concrete was prepared by forming molds, and after 28 days of curing under natural conditions, ecological concrete products were obtained. The method is pollution-free, low-cost, simple and easy to implement, and the product can naturally form pores during the curing process. The obtained product has anti-skid and anti-noise characteristics, and can slowly release N, P, and K to promote vegetation growth while solidifying Pb, Cd, Zn, Cu, Hg and other harmful elements in the sludge; the product can be used for slope care , road greening, etc.

Description

A kind of production method of sludge based eco-concrete goods

Technical field

The present invention relates to the production method of concrete product.

Background technology

Along with the development of Chinese society economy and urbanization, the output of municipal effluent is in continuous growth.Mud is the fittings after the sewage disposal, is a kind of extremely complicated heterogeneous body that is comprised of organic relic, bacterium thalline, inorganic particle, colloid etc.The main characteristic of mud be water ratio up to about 90%, organic content is high, easily degenerates smellyly, and particle is thin, proportion is less.If mud is not carried out ultimate disposal, will bring Re-pollution to environment.At present take landfill as main, and there are a small amount of compost and burning in China to disposal of sludge.The biggest problem of sludge treatment is that " preliminary sludge " water ratio is too high, and later stage dehydration difficulty is large, expense is high.Therefore, no matter be landfill, or compost, burning, effect is all undesirable.Yet mud also is useful Biological resources, how to avoid the secondary pollution of sludge creation and rationally utilize effective constituent in the mud, and be one of study hotspot that needs to be resolved hurrily for a long time.China Patent No.: CN201110057413 discloses a kind of processing method of disposing residual sludge by desulfuration lime, and it is that the excess sludge of pending water ratio 80 ~ 90% and desulfurization lime are sent into mixing reactor; The desulfurization lime adding amount be the excess sludge quality the storage of 20 ~ 60% desulfurization lime by the reactant measuring apparatus with desulfurization lime in the mix and blend reactor, be 10 ~ 20min by stirring or turning over the throwing effect hybrid reaction time, make semi-oriented mud, then send into sludge pelletizer, be broken into the mud granule that particle diameter is 2 ~ 6mm, mud granule imported carry out drying treatment between solar energy drying, the drying room temperature is more than 40 ℃, humidity is below 15%, through the drying treatment of 24 ~ 48h, obtain water ratio and be 7 ~ 15% mud.China Patent No.: CN201110057421 discloses a kind of processing method of utilizing the flyash treating excess sludge, and it specifically may further comprise the steps: 1. be 80 ~ 90% excess sludge with pending water ratio and account for 20 ~ 50% of excess sludge quality and must send into mixing agitator; Fully behind hybrid reaction 5 ~ 15min, sending into the sheet frame water extracter dewaters, obtain water ratio and reduce to 35 ~ 45% mud, sludge pelletizer is after particle diameter is the coarse particles of 3-5mm with sludge crushing, and it is more than 40 ℃ that mud granule is sent between solar energy drying in temperature, humidity is below 15%, through the drying treatment of 24 ~ 48h, moisture percentage in sewage sludge is down to 8 ~ 15%, makes powder equipment through mud and adopts the technical finesse of air-flow high velocity impact, the mud powder directly is 150 ~ 300 orders after processing, and water ratio is 5 ~ 10%.Although above two kinds of methods can both lignin-sludge, cost is higher, and practical value is limited.

Eco-concrete is by material screening, add functional additive, adopt certain technique produced have special construction with function, carrying capacity of environment is little, ecotope phase Harmony is high, and the concrete that can contribute for environmental protection.The appearance of eco-concrete indicates the human attitude more positive, initiatively of having taked in processing concrete material and environment Relations Among process.Eco-concrete is not only as material of construction, and for the mankind construct needed works or buildings, and he is the fusion with nature, physical environment and the eubiosis is had the material of active protection effect.Along with the development of concrete technology, eco-concrete will become for the Sustainable development of the improvement of people's ever-changing environment in next life and society to make larger contribution as special concrete.The function of the eco-concrete of developing at present mainly contains rain penetration, sewage disposal, riverbank bank protection, reduces noise, the noise control sterilization, absorb and remove oxynitride, counterchecking electromagnetic wave and grass planting and fix the sand etc.Ecological coagulation technology of preparing is comparatively ripe in developed country.Be at present research and use one of maximum eco-concrete such as permeable concrete, this concrete is widely applied in developed countries such as Germany, Japan, the U.S., is mainly used in road and road surfacing.China also begins to pay attention to the Greening problem of concrete structure at present, but the preparation method of eco-concrete still has certain limitation.China Patent No.: CN 201110083342 discloses a kind of eco-concrete and preparation method thereof, it is made by weight by following raw materials according: with 10 ~ 15 parts of ordinary Portland cements, 40 ~ 60 parts of quartz sands, 5 ~ 10 parts in water, airentraining agent 0.15 ~ 0.25, modified coal ash 15 ~ 20,10 ~ 15 parts of property titanium dioxide; The preparation method is: starting material prepare-measure-stir-pour into the mold-mechanical pudding-maintenance-demoulding, can be used for the riverbank slope protection works.China Patent No.: CN 200510030133 discloses a kind of vegetation ecological concrete and preparation method thereof, its plant cover concrete prefabricated section by the top layer culture medium layer that is suitable for vegetation growth, be suitable for upper strata cellular concrete layer that vegetation root system runs through, be suitable for the useless masonry substratum mixolimnion in middle level of vegetation root system growth and be suitable for the prefabricated section that lower floor's cellular concrete layer that vegetation root system runs through consists of four-layer structure.Its preparation process is: the 1. upper and lower layer of identical two of first preparation size cellular concrete layers; 2. spread substratum at lower floor's cellular concrete layer, cover the upper strata cellular concrete layer that has made at the middle level substratum, and around wall seal up smooth cement; 3. maintenance is 3 ~ 4 days; 4. cover the top layer culture medium layer at prefabricated section.Prefabricated section is laid on the riverbank, approximately namely grows grass at the top after 14 ~ 20 days, and grass roots runs through the upper, middle and lower and enters outside soil, plays greening and the effect of conserving water and soil.The present invention lays conveniently, can carry out industrialization production.But utilize mud to have no report as the method that starting material prepare eco-concrete.

Summary of the invention

The objective of the invention is treating sludge and vegetation ecological concrete production are combined, a kind of sludge based eco-concrete production method is provided.

Technical scheme of the present invention is: a kind of production method of sludge based eco-concrete goods, it is to be that 2 ~ 20% the mud through filter-press dehydration, 10 ~ 25% fine sand, 40 ~ 55% coarse aggregate, 15 ~ 25% cement, 0.5 ~ 10% water are base-material, and add 0.5 ~ 2% water reducer with weight percentage; Stirring and evenly mixing is placed on the forming mould extrusion molding and prepares concrete; After the demoulding more under field conditions (factors) maintenance obtain finished product after 28 days.

In the technique scheme: described cement is ordinary Portland cement; Described coarse aggregate is rubble, and grade is 5 ~ 16mm, and apparent density is 2500 ~ 2900kg/m ³, piling up porosity is 30 ~ 60%, water-intake rate is 1 ~ 1.5%, silt content＜0.5%; Described water reducer adopts XY-007 series polycarboxylate water-reducer, and water-reducing effect reaches 25 ~ 35%; Described mud is the mud that produces behind Biological Treatment of Wastewater, and wherein moisture is 80 ~ 95%; Described fine sand is common fine sand; Described mud is through filter-press dehydration, and filter-pressing method commonly used comprises filter press technique, gravity concentration method, air supporting method of enrichment, centrifugal concentrating method; Preferred filter press technique; Described mud can be with the various mud that produce in the city domestic sewage treating processes, its water ratio 80 ~ 95%.Described stirring and evenly mixing method is: first whole coarse aggregates+total consumption 50% sludge agitation 0.5 ~ 5min is to mixing; Then add cement+total consumption 30% water and stir 0.5 ~ 5min to mixing; Add again fine sand+total consumption 50% sludge agitation 0.5 ~ 5min to mixing; Adding at last whole water reducers+remaining water stirs more than the 3min.It can also utilize steam-pressing aero-concrete equipment commonly used to carry out aerating to improve porosity.

Major advantage of the present invention:1. present method combine moisture percentage in sewage sludge after the press filtration high and and the characteristic of the strong suction of mud, the concrete preparation only need add moisture on a small quantity, is beneficial to preparation and initial stage moulding, drying; 2. in the concrete preparation process, the rear volume-diminished because mud dewaters gradually can make self-assembling formation porosity characteristic in the concrete formation process; 3. utilize after the moulding in the cellular concrete the slowly release characteristics such as the contained N of mud, P, it is to providing the fertilizer efficiency element for afforestation vegetation in the nursing processes such as side slope, road; 4. the cellular concrete preparation is the process to sludge treatment and recycling simultaneously, has the advantages that to turn waste into wealth; 5. the concrete of preparation has the characteristics such as porous permeable, fertilizer efficiency slowly-releasing, high-strength light.6. cement forms in the during Concrete, and harmful element in the mud is had curing characteristics.7. technique is relatively simple, and goods are with low cost, accounts for 70 ~ 80% of normal concrete; Simultaneously can save the sludge treatment cost, 50 yuan /Ton.8. the method is that a kind of pollution-free, low-cost, simple recycling sludge utilizes new way, and the eco-concrete goods of preparation can be used for the places such as side slope nursing, roadside greening, have wide market application foreground.

Embodiment

Embodiment given below is so that the invention will be further described; but can not be interpreted as it is limiting the scope of the invention; the person skilled in art to some nonessential improvement and adjustment that the present invention makes, still belongs to protection scope of the present invention according to the content of the invention described above.

Example table 1Sludge based eco-concrete preparation prescription

Example table 2Sludge based eco-concrete technical indicator

Example table 3Sludge based eco-concrete 30d leaches concentration of element (unit: ppm)

Above-mentionedly respectively execute example batching and can produce the product that reaches the object of the invention by aforementioned processing method.Embodiments of the invention all can be implemented, and the invention is not restricted to these embodiment.

Claims (6)

1. A production method of sludge-based ecological concrete products, characterized in that, it is the sludge dewatered through pressure filtration, 10-25% fine sand, 40-55% by weight percentage % coarse aggregate, 15-25% cement, 0.5-10% water as the base material, and add 0.5-2% water reducer; mix well and put it in the molding die to extrude to prepare concrete; demoulding After curing for 28 days under natural conditions, the finished product is obtained. 2. the production method of sludge-based ecological concrete product according to claim 1, is characterized in that, described cement is ordinary portland cement; Described coarse aggregate is crushed stone, and particle size is 5 ~ 16mm , the apparent density is 2500~2900kg/m ³ , the bulk porosity is 30~60%, the water absorption is 1~1.5%, and the mud content is <0.5%; the water reducer is XY-007 series polycarboxylic acid The water reducing agent has a water reducing effect of 25-35%; the sludge is the sludge produced after biological treatment of wastewater, in which the water content is 80-95%; the fine sand is ordinary fine sand. 3. according to the production method of the sludge-based ecological concrete product described in claim 1 or 2, it is characterized in that, described sludge is dewatered through pressure filtration, and commonly used pressure filtration method comprises pressure filtration method, gravity concentration method , air flotation concentration method, centrifugal concentration method; preferred filter press method. 4. according to the production method of the described sludge-based ecological concrete product of claim 1 or 2, it is characterized in that, described sludge is the various sludges that produce in the urban domestic sewage treatment process, moisture content 80～95% . 5. The production method of sludge-based ecological concrete products according to claim 1 or 2, characterized in that, the mixing and mixing method is as follows: first all the coarse aggregate + total amount of 50% sludge is stirred for 0.5 ~ 5min Mix until uniform; then add cement + total amount of 30% water and stir for 0.5~5min until uniformly mixed; then add fine sand + total amount of 50% sludge and stir for 0.5~5min until uniformly mixed; finally add all water reducing agent + remaining water Stir for more than 3min. 6. The production method of the sludge-based ecological concrete product according to claim 1 or 2, characterized in that, utilizing commonly used autoclaved aerated concrete equipment to aerate to increase porosity.