(1. 四川大學(xué) 水力學(xué)與山區(qū)河流開(kāi)發(fā)保護(hù)國(guó)家重點(diǎn)實(shí)驗(yàn)室，成都 610065；
2. 四川大學(xué) 水利水電學(xué)院，成都 610065；
3. 四川大學(xué) 深地科學(xué)與工程教育部重點(diǎn)實(shí)驗(yàn)室，成都 610065；
4. 昆明理工大學(xué) 國(guó)土資源工程學(xué)院，昆明 650093)
摘 要: 超細(xì)尾砂已成為金屬礦山充填處理的最大宗固體廢料，流變模型是刻畫超細(xì)尾砂料漿流動(dòng)特性及確定管輸參數(shù)的主要依據(jù)。基于超細(xì)顆粒絮凝結(jié)構(gòu)形成機(jī)制，引入結(jié)構(gòu)參數(shù)來(lái)描述超細(xì)尾砂料漿剪切響應(yīng)過(guò)程。采用旋轉(zhuǎn)黏度計(jì)對(duì)某礦山質(zhì)量分?jǐn)?shù)72%、74%、76%和水泥添加量240、260 kg/m3的超細(xì)尾砂充填料漿進(jìn)行24組不同剪切強(qiáng)度下的流變測(cè)試。結(jié)果表明：在恒定剪切速率下，料漿剪切應(yīng)力隨著剪切時(shí)間延長(zhǎng)而逐漸減小，最后趨于穩(wěn)定；任意剪切時(shí)間下，剪切應(yīng)力與剪切速率(＞20 s-1)的關(guān)系近似滿足Bingham模型，且Bingham回歸參數(shù)具有明顯的時(shí)變性。這些宏觀規(guī)律的原因可歸結(jié)于漿體結(jié)構(gòu)參數(shù)的變化。基于此，構(gòu)建了關(guān)于漿體剪切強(qiáng)度和剪切時(shí)間的雙變量流變模型，模型中7個(gè)參數(shù)均具有物理含義。通過(guò)試驗(yàn)數(shù)據(jù)對(duì)模型進(jìn)行了驗(yàn)證，擬合得到試驗(yàn)配比下的超細(xì)尾砂料漿流變參數(shù)，最大屈服應(yīng)力和最大塑性黏度范圍分別為120~220 Pa和1.7~7.2 Pa·s，可為啟動(dòng)壓力計(jì)算提供參考；極限屈服應(yīng)力和極限塑性黏度范圍分別為20~120 Pa和0.5~3.2 Pa·s，可為漿體穩(wěn)態(tài)流動(dòng)阻力計(jì)算提供參考。另外，介紹了新流變模型的適用條件及應(yīng)用方法，并與現(xiàn)有流變模型進(jìn)行了對(duì)比討論。
關(guān)鍵字: 充填料漿；超細(xì)尾砂；絮凝結(jié)構(gòu)；觸變性；流變參數(shù)；流變模型
（1. College of Water Resources and Hydropower, Sichuan University, Chengdu 610065, China;
2. State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu 610065, China;
3. Key Laboratory of Deep Earth Science and Engineering, Ministry of China, Sichuan University, Chengdu 610065, China;
4. Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming 650093, China）
Abstract:Ultrafine tailings have become the largest solid waste in metal mine filling treatment. The rheological model provides a theoretical foundation for capturing its flow characteristics and determining the pipeline transportation parameters. To describe the shear response process of ultrafine tailings slurry, firstly, the concept of the structural parameter in this paper was introduced based on the formation mechanism of ultrafine particle flocculation structure. Then, a rotary viscometer was used to conduct 24 groups of rheological tests on the ultrafine tailings slurry with mass fractions of 72%, 74% and 76% and cement contents of 240 and 260 kg/m3under different shear strengths. The results show that under constant shear strength, the shear stress of the slurry gradually decreases with the increase of shear time, and ultimately tends to be stable; under any shear time, the shear stress and shear rate (＞20 s-1) approximately satisfy the Bingham model, and the Bingham regression parameters are obviously time-varying. The reason for these macroscopic laws can be attributed to the change of the slurry structural parameters. According to these evidences, a bivariate rheological model of the ultrafine tailings slurry with respect to shear strength and shear time was proposed, in which seven parameters have certain physical meanings. The proposed model was verified by the experimental data, and the rheological parameters of the ultrafine tailings slurry with the given mix are obtained by the best fitting. The maximum yield stress and maximum plastic viscosity range from 120 Pa to 220 Pa and from 1.7 Pa·s to 7.2 Pa·s, respectively, which can provide a reference for the calculation of the starting pressure; the range of the limit yield stress and plastic viscosity are from 20 Pa to 120 Pa and from 0.5 Pa·s to 3.2 Pa·s, respectively, which can give a reference for the calculation of the steady-state flow resistance of the slurry. Lastly, the applicable conditions and methods of the proposed rheological model are discussed, and also compared with the existing rheological model. The research results can provide theoretical and experimental basis for mine filling design.
Key words: filling slurry; ultrafine tailings; flocculation structure; thixotropy; rheological parameter; rheological model
