(1. 河南理工大學(xué) 土木工程學(xué)院，焦作 454000；
2. 北京科技大學(xué) 土木與資源工程學(xué)院，北京 100083；
3. 山東黃金集團(tuán)有限公司充填工程實(shí)驗(yàn)室，萊州 261441)
摘 要: 為研究攪拌對(duì)膏體流變性能的影響，通過控制攪拌速度制備膏體樣品，并測(cè)試其細(xì)觀結(jié)構(gòu)、流變、電位及離子濃度等參數(shù)，從物理化學(xué)角度分析速度對(duì)膏體流變的影響。結(jié)果表明：膏體攪拌存在速度閾值(本研究中該值為1000~1500 r/min)，當(dāng)攪拌速度小于閾值時(shí)，由于膏體中各類膜包裹的顆粒被攪拌分散，細(xì)觀結(jié)構(gòu)尺寸隨攪拌速度增加而變小，膏體流變參數(shù)隨攪拌速率增加而降低，其流變曲線符合Bingham模型；而當(dāng)攪拌速度超過閾值時(shí)，強(qiáng)攪拌剪切促進(jìn)了早期水化物及無機(jī)鹽離子溶解到溶液中，其離子濃度升高，顆粒表面電勢(shì)由-0.7655 mV變?yōu)?0.4760 mV，測(cè)得細(xì)觀結(jié)構(gòu)及流變參數(shù)均隨攪拌速度增加而變大，且流變曲線更符合H-B模型(n＜1)。結(jié)合Hattori-lzumi理論和Debye-Hückel理論，通過引入剪切速率因子，建立顆粒表面電化學(xué)與吸附力、流變與顆粒聚集狀態(tài)關(guān)系方程，分析了攪拌剪切對(duì)膏體流變特征的影響機(jī)制，為膏體攪拌技術(shù)發(fā)展提供理論支撐。
關(guān)鍵字: 全尾砂膏體；攪拌速度；細(xì)觀結(jié)構(gòu)；雙電層；流變模型
（1. School of Civil and Engineering, Henan Polytechnic University, Jiaozuo 454000, China;
2. School of Civil and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China;
3. Filling Engineering Laboratory of Shandong Gold Group, Laizhou 261441, China）
Abstract:In order to study the effect of mixing on the rheological properties of cemented paste backfill(CPB), the CPB samples were prepared by controlling the mixing speed, and the parameters such as microstructure, rheology, potential and ion concentration were tested. The effect of mixing speed on the rheological properties of the paste was analyzed from the perspective of physics and chemistry. The results show that there is a speed threshold for CPB mixing (in this study, the value is in the range from 1000 r/min to 1500 r/min). When the mixing speed is less than the threshold, because all kinds of film wrapped particles in the CPB are mixed and dispersed, the mesostructure size decreases with the increase of mixing speed, and the rheological parameters of the CPB decrease with the increase of mixing speed. The rheological curve conforms to Bingham model. When the mixing speed exceeds the threshold, strong mixing shear promotes the dissolution of early hydrate and inorganic salt ions into the solution, the ion concentration increases, and the particle surface potential changes from -0.7655 mV to 0.476 mV. The measured microstructure and rheological parameters increase with the increase of mixing speed, and the rheological curve is more in line with the H-B model (n＜1). Combined with Hattori-lzumi theory and Debye-Hückel theory, by introducing shear rate factor, the relationship equations between particle surface electrochemistry and adsorption force, rheology and particle aggregation state are established, and the influence mechanism of mixing shear on the rheological characteristics of paste is analyzed, which provides theoretical support for the development of paste mixing technology.
Key words: cemented paste backfill; mixing speed; microstructure; electric double layer; rheological model
