Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Method of cement kiln co-processing for calcium-added and passivated town sludge

A technology of co-processing and cement kiln, which is applied in the direction of water/sludge/sewage treatment, sludge treatment, chemical instruments and methods, etc., can solve the problems of serious secondary pollution, multiple fuels, consumption, etc., to avoid landfill, Fuel saving and cost reduction effects

Active Publication Date: 2014-01-01
南京希捷环保科技有限公司
View PDF3 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] (2) The source and nature of sewage are unstable: the influent of small and medium-sized cities and towns includes industrial sewage and domestic sewage, and the proportion of industrial wastewater is relatively high.
[0007] (4) There are many kinds of heavy metals in urban sludge, and the content difference is significant: due to the high proportion of industrial sewage in the influent water, and the nature of industrial enterprises is significantly different, resulting in a wide variety of heavy metals in urban sludge, and the content difference is significant, As , Cd, Ni, Pb, Cr, Cu, and Zn vary widely, with a range of up to several thousand mg / kg, which leads to serious environmental pollution and high-concentration heavy metal leachate in the process of urban sludge treatment and disposal. Serious secondary pollution
[0008] These characteristics of urban sludge severely limit the use of existing sludge treatment technologies, while the low organic matter content makes composting unfavorable for smooth development, and the high heavy metal concentration limits the agricultural use and landfill treatment of urban sludge composting products, which also makes The secondary pollution in the incineration process is serious, and the low volatile matter, high ash content and low received base heat value lead to the consumption of more fuel in the incineration process
[0009] The environmental problems caused by urban sludge have not yet attracted enough attention, and targeted treatment technologies are also very scarce

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method of cement kiln co-processing for calcium-added and passivated town sludge
  • Method of cement kiln co-processing for calcium-added and passivated town sludge
  • Method of cement kiln co-processing for calcium-added and passivated town sludge

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0035] A kind of urban sludge with a moisture content of 78.2%, a volatile matter content of 18.1%, heavy metals Zn, Cu, Cr, and Ni contents of 1046mg / kg, 293mg / kg, 244mg / kg, and 221mg / kg, respectively, Sr, Mn , Ba content are 766mg / kg, 535mg / kg and 386mg / kg respectively. Add 10% (mass percentage) waste lime, transport it to the sludge mixing mixer with a screw conveyor, fully stir it, and stack it naturally for 7 days under direct sunlight. The water content of the mixture of urban sludge and waste lime is 40%. Calculated based on the dry weight of urban sludge and waste lime, mixed with raw meal (see Table 1 for composition) at a replacement ratio of 2%, to meet the SM=2.5, IM=1.5, KH=0.9 of clinker. The clinker calcination method is as follows: the uniform mixture of urban sludge and waste lime is uniformly mixed with cement raw meal, and then pressed with water to form a φ100mm×15mm green sheet. After drying at 105°C for 24 hours, raise the temperature to 1450°C at a rate...

Embodiment 2

[0040] Town sludge properties are the same as in Example 1. Add 15% (mass percentage) waste lime, transport it to the sludge mixing mixer with a screw conveyor, fully stir it, and stack it naturally for 7 days under direct sunlight. The water content of the mixture of urban sludge and waste lime is 38%. Calculated based on the dry weight of urban sludge and waste lime, mixed with raw meal (see Table 1 for composition) at a replacement ratio of 5%, to meet the requirements of SM=2.4, IM=1.5, and KH=0.9 for clinker. The clinker calcining method is the same as in Example 1.

[0041] After the calcined Portland cement clinker is tested, the four main components in the clinker are tricalcium silicate (C 3 S), dicalcium silicate (C 2 S), tricalcium aluminate (C 3 A) and tetracalcium aluminoferrite (C 4 AF) content were 56%, 20%, 7.9% and 9.2%.

[0042] After calcination, the compressive strengths of ordinary Portland cement 1d, 3d and 28d are 11MPa, 22MPa and 54MPa respectively...

Embodiment 3

[0045] Town sludge properties are the same as in Example 1. Add 20% (mass percentage) waste lime, transport it to the sludge mixing mixer with a screw conveyor, fully stir it, and stack it naturally for 7 days under direct sunlight. The water content of the mixture of urban sludge and waste lime is 30%. Calculated based on the dry weight of urban sludge and waste lime, mixed with raw meal (see Table 1 for composition) at a replacement ratio of 10%, to meet the SM=2.5, IM=1.5, KH=0.9 of clinker. The clinker calcining method is the same as in Example 1.

[0046] After the calcined Portland cement clinker is tested, the four main components in the clinker are tricalcium silicate (C 3 S), dicalcium silicate (C 2 S), tricalcium aluminate (C 3 A) and tetracalcium aluminoferrite (C 4 AF) content were 53%, 20%, 8.1% and 9.0%.

[0047] After calcination, the compressive strengths of ordinary Portland cement 1d, 3d and 28d are 10MPa, 21MPa and 51MPa, respectively. Other indicators...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
compressive strengthaaaaaaaaaa
compressive strengthaaaaaaaaaa
compressive strengthaaaaaaaaaa
Login to View More

Abstract

The invention discloses a method of cement kiln co-processing for calcium-added and passivated town sludge and solves the technical problems that the content of organic matters in the town sludge is lower while the content of heavy metals in the town sludge is higher, the nature of the sludge is not stable, the moisture content of the sludge is high and the sludge is difficult to transport. The implementation steps of the method are as follows: firstly, the constituents and the moisture content of the town sludge are tested, the pH value of the town sludge is usually between 6 and 8, and when the sludge meets leachate within the pH value range or in the landfilling state, the heavy metals are dissolved out easily, and the increasing of the pH value of the sludge is beneficial for passivation of the heavy metals and reduction of dissolution of the heavy metals; the town sludge is mixed with waste lime to ensure that the pH value of the mixture is between 9 and 10, and the mixture is kept stable at room temperature for 2-7 days; and the mixture enters a novel dry-process cement kiln from below a predecomposition furnace, silicon and calcium in the sludge and calcium in the lime can be used to produce silicate cement, and the organic matters in the sludge can be burnt so as to replace partial cement kiln fuel. The method of the cement kiln co-processing for the calcium-added and passivated town sludge is an economical, fuel-saving and low-pollution method for resource utilization of the town sludge.

Description

technical field [0001] The invention relates to a method for co-processing cement kiln after urban sludge is increased in calcium and passivated, in particular to a method for harmless and resourceful utilization of urban sludge containing heavy metals, and belongs to the technical field of solid waste treatment. Background technique [0002] my country's urban sewage treatment facilities have undergone high-speed construction during the "Tenth Five-Year Plan" and "Eleventh Five-Year Plan" periods, and have formed a large-scale treatment capacity. As of the end of September 2010, the accumulated sewage treatment capacity of cities, counties and some key towns (hereinafter referred to as "towns") nationwide has reached 169 million m 3 / d; Among them, 36 large and medium-sized cities (municipalities directly under the Central Government, provincial capitals and cities with separate state planning) have 376 sewage treatment plants with a treatment capacity of 43.68 million m 3...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): C02F11/00C04B7/24
CPCY02P40/10Y02W10/37
Inventor 王雷李润东魏砾宏李彦龙徐杰贺业光孙洋杨天华刘耀鑫
Owner 南京希捷环保科技有限公司
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com