【摘要】：爐底渣是火力發(fā)電廠中燃煤在鍋爐或其他燃燒設(shè)備燃燒后經(jīng)排渣口排出的工業(yè)廢棄物,根據(jù)鍋爐形式的不同主要分為煤粉爐底渣、固硫型流化床爐底渣和非固硫型流化床爐底渣三種,不同類(lèi)型鍋爐產(chǎn)生的底渣成分存在差異。電廠燃煤燃燒排放的爐底渣日益增多,不僅占用寶貴的土地資源,而且造成多種環(huán)境污染。因此,綜合開(kāi)展?fàn)t底渣的高效循環(huán)利用尤為重要。本文針對(duì)爐底渣在制備地質(zhì)聚合物時(shí)綜合利用率低、激發(fā)劑較為單一且用量大的問(wèn)題,采用非固硫型循環(huán)流化床爐底渣作為唯一原料,探索性的將不同種類(lèi)的堿激發(fā)劑與鹽激發(fā)劑混合作為復(fù)合激發(fā)劑制備力學(xué)性能優(yōu)良的爐底渣基地質(zhì)聚合物,對(duì)制備的試件進(jìn)行力學(xué)性能分析及各種礦物相、微觀形貌表征。結(jié)果表明:在堿-鹽復(fù)合激發(fā)劑中,當(dāng)堿激發(fā)劑Na2SiO3摻量為7.7wt%,鹽激發(fā)劑Na2SO4摻量為0.5wt%時(shí),制備的爐底渣基地質(zhì)聚合物試件在室溫養(yǎng)護(hù)28d齡期的抗壓強(qiáng)度高達(dá)46.94 MPa,較單一堿(Na2SiO3)激發(fā)制備試件的抗壓強(qiáng)度增加了15.8%。XRD、SEM以及IR結(jié)果表明:堿-鹽復(fù)合激發(fā)加速了爐底渣中莫來(lái)石、石灰的水化反應(yīng),生成了纖維狀的鈣礬石(AFt)以及大量無(wú)定形的地質(zhì)聚合物凝膠,導(dǎo)致Si-O鍵的非對(duì)稱伸縮振動(dòng)吸收以及Si-O鍵的彎曲振動(dòng)吸收均發(fā)生了位移。采用水鎂石纖維對(duì)堿-鹽復(fù)合激發(fā)爐底渣基地質(zhì)聚合物進(jìn)行強(qiáng)化增韌研究,結(jié)果表明:當(dāng)水鎂石纖維摻量為0.8wt%時(shí),增韌效果最佳,28d齡期的抗壓強(qiáng)度達(dá)到50.69 MPa,抗折強(qiáng)度為9.14MPa,較零纖維摻量的抗折強(qiáng)度(7.22 MPa)提高了26.59%。XRD、MIP及SEM結(jié)果表明水鎂石纖維的加入并未改變地質(zhì)聚合物的礦物相組成,堿-鹽復(fù)合激發(fā)爐底渣水化反應(yīng)生成的無(wú)定形凝膠將水鎂石纖維緊緊包裹,纖維承載橋連拔接的作用;纖維增韌地質(zhì)聚合物的孔隙率減小,小于20nm的孔體積百分?jǐn)?shù)增加了17.23%,平均孔徑變小,試件更加致密,力學(xué)性能提高�？疾炝怂V石纖維增韌堿-鹽復(fù)合激發(fā)爐底渣基地質(zhì)聚合物耐久性能,結(jié)果表明:堿-鹽復(fù)合激發(fā)爐底渣基地質(zhì)聚合物具有優(yōu)良的耐高溫、耐海水侵蝕性能,但抗凍融性能較差;水鎂石纖維增韌堿-鹽復(fù)合激發(fā)爐底渣基地質(zhì)聚合物試件的耐久性能優(yōu)于未增韌試件。隨著煅燒溫度的升高,抗壓強(qiáng)度先升高后降低,煅燒800℃時(shí),增韌試件的抗壓強(qiáng)度仍高達(dá)51.19 MPa;經(jīng)過(guò)28個(gè)侵蝕周期,纖維增韌試件的抗壓強(qiáng)度為41.83 MPa,抗折強(qiáng)度為4.64 MPa;增韌試件最高可承受40個(gè)凍融循環(huán),因此,抗凍融性能有待提高。
[Abstract]:The bottom slag is the industrial waste discharged from the boiler or other combustion equipment after burning in the thermal power plant. According to the different boiler forms, it is mainly divided into the pulverized coal furnace bottom slag, The composition of bottom slag produced by different types of boiler is different from that of fluidized bed slag of fixed sulfur type and that of non-sulfur type fluidized bed slag. The bottom slag discharged from coal combustion in power plant is increasing day by day, which not only occupies valuable land resources, but also causes many kinds of environmental pollution. Therefore, it is particularly important to comprehensively develop the efficient recycling of bottom slag. In order to solve the problem of low comprehensive utilization ratio, single activator and large amount of activator in the preparation of geopolymer, the non-sulfur-fixing circulating fluidized bed bottom slag is used as the sole raw material. Different kinds of alkali activator and salt activator were used as composite activators to prepare the base polymer with excellent mechanical properties. The mechanical properties of the samples were analyzed and all kinds of mineral phases were characterized. The results show that when the amount of alkali activator Na2SiO3 and salt activator Na2SO4 is 7.7wt and 0.5wt% respectively, The compressive strength of the base polymer specimen prepared by the furnace bottom slag is up to 46.94 MPa, at room temperature curing for 28 days, and the compressive strength of the sample excited by single base (Na2SiO3) is increased by 15.8. XRD. The results of SEM and IR show that the hydration reaction of mullite and lime in furnace slag is accelerated by the combination of alkali and salt, resulting in the formation of fibrous ettringite (AFt) and a large number of amorphous geopolymer gels. The asymmetric stretching vibration absorption of the Si-O bond and the bending vibration absorption of the Si-O bond are all shifted. Brucite fiber was used to strengthen and toughen the base polymer of alkali-salt activated slag. The results showed that when the content of brucite fiber was 0.8wt%, the toughening effect was the best, and the compressive strength of 28d age was 50.69 MPa,. The flexural strength was 9.14 MPA, and the flexural strength (7.22 MPa) was increased by 26.59.XRDD-MIP and SEM. The results showed that the addition of brucite fiber did not change the mineral phase composition of geopolymers. The amorphous gel formed by the alkali-salt compound excitation slag hydration reaction tightly encapsulates brucite fiber, and the fiber carries the function of bridge connection and pull-out. The porosity of geopolymer toughened by fiber decreases, the percentage of pore volume less than 20nm increases 17.233.The average pore size becomes smaller, the specimen becomes denser and the mechanical properties are improved. The durability of brucite fiber toughened alkali-salt composite activated slag base polymer was investigated. The results showed that alkali-salt composite activated furnace bottom slag base polymer had excellent resistance to high temperature and seawater erosion. But the freeze-thaw resistance is poor; The durability of brucite fiber toughened alkali-salt composite activated slag base polymer specimen is better than that of untoughened specimen. With the increase of calcination temperature, the compressive strength increased first and then decreased. At 800 鈩，

本文編號(hào)：2428421