碱渣固化试验初步研究.doc

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摘  要

我国是世界上纯碱年产量最多的国家，占世界总量的1/3以上。现阶段，国内纯碱生产多数采用氨碱法，占纯碱总产量的60%以上。但是氨碱法制碱过程产生大量的副产物（碱渣），长期下来大量堆积形成的“碱渣山”占地面积大、极易起尘，严重影响了群众的正常生活及地区环境，而且不能自行凝固，在地震等外因素作用下，还可能出现塌方和大滑坡。现如今土地资源凸显紧缺，可供堆放碱渣的滩涂、洼子已不复存在，因而急需研究碱渣田合理处置、再利用方法。

目前国内对于碱渣的处理有碱渣回填造地、筑坝填埋、吹填贮放以及作为土壤改良剂等，但是对于大规模碱渣的有效处理方式则是将碱渣作为碱渣固化土来利用，碱渣固化土是在碱渣土中加入固化剂混合料形成的特殊工程用土，用于填筑工程。然而碱渣具有高含水量、高压缩性、失水性差、强度低、孔隙率小等特点导致对其处理一直存在很大的困难。本文以天津港北疆港区碱渣为研究对象，通过一系列的室内试验对高含水率碱渣的固化改良技术做了系统的研究，以及提出了碱渣田就地浅层固化快速形成施工便道等技术，主要内容和结论如下：

（1）根据相关的研究经验，结合碱渣的特点，考虑经济性以及实用性，选择固化剂组成成分，分别为高炉矿渣微粉（GGBS）、水泥。

（2）开展GGBS单一固化试验以及水泥单一固化试验，分别从不同掺量、不同养护龄期下的无侧限抗压强度进行比较分析。试验结果表明：当采用单一GGBS进行固化时，碱渣固化土的早期强度大于相同水泥掺量下的早期强度，但GGBS在较高掺量下，碱渣固化土后期强度发展变缓。

（3）基于对单一固化剂固化效果以及经济性考虑，开展复合型固化剂试验，分别从不同掺量、不同养护龄期下的强度进行比较分析。采用模糊数学分析方法，确定3%水泥+8%GGBS的固化剂配比为本试验所取原状碱渣的优选配比。

（4）开展优选配比下碱渣固化土的一维压缩试验，研究碱渣固化土的压缩变形特性和结构屈服应力等工程特性。结果表明，碱渣固化土经过28d养护后达到了中压缩性土的标准，但是当荷载超过碱渣固化土的屈服应力时，其压缩系数将出现陡增。

关键词：碱渣；GGBS；优化研究；无侧限抗压强度；压缩试验；屈服应力 

ABSTRACT

Our country is the world's largest soda residue annual country, accounting for more than one-third of the world total. At this stage, the majority of domestic soda residue production using ammonia soda, accounting for more than 60% of total production. But ammonia soda process produces a large amount of byproducts (soda residue), down to the large accumulation of long-term formation of the "soda residue Hill", an area of large, easy dusting, seriously affected the normal life of the people and the local environment, but can not self solidified in earthquake endures factors may also occur landslides and large landslides. Now highlight the scarcity of land resources, piling up the beach for caustic sludge has ceased to exist, and thus in urgent need of proper disposition of field research caustic sludge, recycling methods.

Currently treatment for soda residue including backfill stretched, damming landfill, reclamation storage and used as a soil conditioner, but for the effective treatment of large-scale is to improve soda residue as stabilized soil to use. Soda residue solidified soil is added to the soil hardener mix with soil formed a special project for the reclamation project. However soda residue with high water content, high compression, poor dehydration, low strength, low porosity and other characteristics lead to its treatment there has been very difficult. In this paper, using the soda residue from Tianjin Port Northern Port for the study through a series of laboratory tests. To do a systematic study on the high moisture content of the soda residue solidification improved technology and propose shallow cured in a caustic sludge field in order to quickly form construction of access roads , the main content and conclusions are as follows: 

(1) According to relevant research experience, combined with the characteristics of soda residue, considered the economic and practical, it selects hardener components:blast furnace slag powder (GGBS) and cement.

(2) By carring out GGBS single test and curing cement single test, it adopts a comparative analysis of different dosage and different curing period unconfined compressive strength.The results show that: when using the single GGBS for curing, soda residue solidified soil early strength greater than under the same cement content, but when GGBS is at higher dosage, the late strength develop slowly.

(3) Based on a single effect as well as economic considerations and carring out the compound type curing agent text. It analyzes different content and the intensity under different curing period. Fuzzy mathematical analysis methods to determine the 3% + 8% GGBS cement curing agent ratio of undisturbed caustic preferred ratio.

(4) By carring out the preferably ratio stabilized soil one-dimensional compression test, study soda residue solidified soil compressive deformation characteristics and structural characteristics of yield stress and other projects. The results showed that after 28d, soda residue solidified soil conservation up to the moderate compression of the soil, but when the load exceeds the yield stress of soda residue solidified soil, the compression factor will appear steep.

Key words：soda residue；GGBS；optimization study；unconfined compressive strength；compression tests；yield stress 

第1章 绪论

1.1 研究碱渣的背景和意义

我国是发展中国家，天然碱不够丰富，而纯碱又是重要的化工原料。但是氨碱法生产纯碱过程中会产生大量的废渣（碱渣），天津碱厂每年排出的碱渣废液量就达到 ，其中固态碱渣为 ，自从建厂以来排放的碱渣已超过1500万吨[1]，碱渣占地面积大、方量多，常年露天堆放，极易起尘，严重影响了群众的正常生活及地区新区环境，而且现如今土地资源凸显紧缺，可供堆放碱渣的滩涂、洼子已不复存在。碱渣的大量堆放严重影响和阻碍该地区的开发、建设和经济发展，因而对碱渣的研究已经引起了高度的重视。然而碱渣具有含水量高、压缩性大、抗剪强度低、结构性极差、承载能力低等特点，必须进行处理才能满足相应的道路交通及厂房用地等后续工程建设的需要。国内学者对于堆积年代较久碱渣的处理以及在工程实践中的应用进行了许多的探索和研究。。。