金川镍矿早强胶凝材料开发及充填料浆管输特性研究

发布时间：2018-05-06 03:04

本文选题：金川镍矿 + 充填采矿　；参考：《北京科技大学》2015年博士论文

【摘要】：金川镍矿是以埋藏深、矿岩破碎、矿体厚大和地应力高为特点的大型难采硫化铜镍矿床。通过采矿技术研究和工程实践,金川镍矿最终选择了生产能力低和采矿成本高的下向分层进路胶结充填采矿法。目前金川镍矿主要以棒磨砂作为充填骨料和以水泥作为充填胶凝材料,并采用高浓度和高灰砂比的充填料浆,其充填成本之高在国内外并不多见,因此金川企业面临巨大的经济压力,并影响着企业在国际上的竞争力。降低充填采矿成本和提高采矿经济效益是金川镍矿面临的最迫切问题。本文以金川集团公司重大科研项目“新型充填胶凝材料开发与固体废弃物利用研究”及科技攻关项目“金川特大型复杂难采矿体开采支撑理论与关键技术”为依托,针对金川矿区周围可以利用的固体废弃物,开展基于金昌瓮福化工厂磷石膏、金昌铁厂水淬渣的早强充填胶凝材料开发以及高浓度充填料浆管道输送特性研究,为提高金川充填采矿经济效益和固体废弃物利用奠定基础。本文主要开展的研究工作及获得的主要结果如下： (1)金川镍矿下向分层胶结充填采矿法要求3d、7d、28d的充填体强度分别达到1.5MPa、2.5MPa、5.0MPa。随着矿山采矿进入千米深井,确定与深部采场地压相匹配的充填体强度,是实现深部安全、高效开采的关键。通过搜集整理金川地应力实测数据,利用改进的BP神经网络建立地应力预测模型,进行深部地应力场回归分析预测,揭示金川矿区地应力分布规律。在此基础上,采用多种充填体强度设计方法,确定了金川目前的充填体设计强度仍适用于深部高地应力采场安全采矿要求。 (2)针对下向分层胶结充填采矿法对充填体早期强度的要求,金川镍矿目前采用1：4高灰砂比和77%-79%高浓度料浆的管道自流输送充填技术,不仅充填采矿成本高(165.00元/m3),而且对料浆自流输送技术提出更高要求。为此,开展了利用磷石膏和水淬渣为主要组分的早强充填胶凝材料研发。首先对磷石膏和水淬渣等充填物料进行物化特性分析,然后,开展不同激发剂配方的正交试验。采用极差分析、神经网络建模预测和回归分析等研究方法,揭示了磷石膏-矿渣基早强胶凝材料充填体强度与激发剂掺量的关系与变化规律,获得了磷石膏-矿渣基早强胶凝材料的最佳配方为：生石灰5%,磷石膏25%,NaOH为2%,芒硝2.5%和矿渣微粉65.5%。通过对最佳配方的胶凝材料进行强度验证试验,获得1：4胶砂比和78%浓度的新型胶凝材料胶砂3d、7d、28d的充填体抗压强度分别达到1.85MPa、3.06MPa、8.69MPa,满足金川深部采矿对充填体强度的要求(R3≥1.5MPa、 R7≥2.5MPa、R28≥5MPa)。新型早强胶凝材料的强度优于32.5水泥,成本仅是32.5水泥成本的66%。 (3)为了进一步优化磷石膏-矿渣基早强充填胶凝材料特性,采用SEM和XRD技术分析,研究新型早强充填胶凝材料水化机理和强度形成过程。研究发现,矿渣微粉在以磷石膏为主要的复合激发剂作用下发生水化反应,其主要水化产物是水化硅酸钙凝胶(C-S-H)和钙矾石(AFt)。芒硝早强剂为早期水化反应创造了适宜的环境,使早期水化反应速度加快。水化硅酸钙凝胶(C-S-H)的大量生成沉积,在充填体中起到充填黏结作用。钙矾石(AFt)的大量生成发育,在充填体中承担穿插支撑作用。随着水化龄期的延长,水化反应改变了充填体的成分,吸收了充填体中的水分,使充填体的结构致密,从而提高了充填体的强度。 (4)为了将磷石膏-矿渣基早强充填胶凝材料应用于金川矿山,针对金川矿山充填系统和高浓度料浆管道输送要求,开展了磷石膏-矿渣基早强充填胶凝材料高浓度料浆流动特性参数测试以及管道输送特性的研究。研究结果表明,磷石膏-矿渣基早强胶凝材料的充填料浆流动性与水泥充填料浆的流动性基本相同,新型早强胶凝材料充填料浆完全满足金川矿山对充填料浆的流动性要求(稠度≥9cm、塌落度≥20cm、分层度≤2.0cm)。研究还发现,在料浆浓度为78%和胶砂比为1：4的条件下,早强充填胶凝材料料浆属于宾汉流体,可近似视为均质流体,在管道输送中呈现层流状态。利用充填料浆流动特性测试结果,采用FLUENT软件进行新型早强充填胶凝材料料浆在管道中输送的数值模拟分析,揭示了高浓度充填料浆流经直管、弯管和长距离阶梯管道时的料浆流速、流核、压强以及摩擦阻力的变化规律。结果表明,采用磷石膏-矿渣基早强充填胶凝材料替代水泥,可以利用目前金川矿山高浓度自流充填系统进行新型充填胶凝材料的工业化应用,从而实现金川矿山深部资源安全、高效、绿色和经济开采。
[Abstract]:Jinchuan nickel ore is a large and difficult copper nickel sulfide deposit, which is characterized by deep burial, broken ore rock, heavy ore body and high ground stress. Through the research of mining technology and engineering practice, Jinchuan nickel mine has finally chosen low production capacity and high mining cost in lower direction stratified route filling mining. At present, the Jinchuan nickel mine is mainly filled with bar grind as filling. Filling aggregate and cement as filling cementitious material and filling slurry with high concentration and high ash sand ratio are not much more common at home and abroad. Therefore, Jinchuan enterprises are facing enormous economic pressure and influence the competitiveness of enterprises in the world. To reduce the cost of filling and mining and to improve the economic benefit of mining is the Jinchuan nickel mine. The most urgent problem coming.
This paper is based on the major scientific research project of Jinchuan group "new filling cementitious material development and solid waste utilization research" and scientific and technological breakthrough project "Jinchuan super complex and difficult mining body mining support theory and key technology". In view of the solid waste that can be used around Jinchuan mining area, Jinchang Weng Fu chemical industry is carried out. The development of early strong filling cementitious material for water quenched slag in Jinchang iron plant and the research on pipeline transportation characteristics of high concentration filling slurry are studied, which lays the foundation for improving the economic benefit of filling mining in Jinchuan and the use of solid waste.
The main research work and main results obtained are as follows:
(1) the subgrade cemented filling mining method in Jinchuan nickel mine requires that the strength of 3D, 7d, 28d filling body reach 1.5MPa, 2.5MPa, 5.0MPa., respectively, with the mining of mine mining into a kilometer deep well, and the strength of the filling body matching the deep mining ground pressure is the key to realize the deep safety and high efficiency. Based on the improved BP neural network, the ground stress prediction model is established and the deep ground stress field regression analysis is made to reveal the distribution law of ground stress in Jinchuan mining area. On this basis, the design strength of various filling body strength is adopted to determine that the present design strength of the filling body in Jinchuan is still applicable to the safety mining requirements of the deep high ground stress stope.
(2) in view of the requirements for the early strength of backfilling, Jinchuan nickel mine is currently using 1:4 high ash sand ratio and 77%-79% high concentration slurry for pipeline self flow filling and filling technology, not only with high cost of filling mining (165 yuan /m3), but also higher requirements for the self flow technology of slurry. For this reason, the use of phosphorus stone is carried out. Gypsum and water quenched slag are the main components of early strength filling cementitious materials.
Firstly, the physicochemical properties of phosphogypsum and water quenched slag were analyzed. Then, the orthogonal experiment of different activator formulations was carried out. The relationship between the strength of the phosphogypsum slag based early strong cementitious material and the content of the activator was revealed by the methods of extreme analysis, neural network modeling prediction and regression analysis. The best formula for phosphogypsum slag based early strength cementing material is as follows: quicklime 5%, phosphogypsum 25%, NaOH 2%, mirabilite 2.5% and slag powder 65.5%..
The strength verification test of the cementitious material for the best formula shows that the compressive strength of the filling body of the new cementitious material 3D, 7d and 28d is 1.85MPa, 3.06MPa, 8.69MPa, which can meet the requirements of the strength of the filling body in the deep mining of Jinchuan (R3 > 1.5MPa, R7 > 2.5MPa, R28 is more than). The new type of early strong cementitious material in Jinchuan. The strength of the material is better than that of 32.5 cement, and the cost is only 66%. of 32.5 cement cost.
(3) in order to further optimize the characteristics of the early strong filling cementitious material of phosphogypsum slag base, the hydration mechanism and strength formation process of the new early strong filling cementitious material were studied by SEM and XRD technology. The study found that the slag powder was hydrated under the action of phosphogypsum as the main compound activator, and the main hydration product was hydration. Calcium silicate gel (C-S-H) and Ettringite (AFt). The early strength agent of mirabilite created a suitable environment for early hydration reaction and accelerated the early hydration reaction. A large number of hydrated calcium silicate gel (C-S-H) was formed and deposited in the filling body. The formation and development of the ettringite (AFt) was produced in a large amount, and the interspersed support was carried out in the filling body. With the prolongation of the age of hydration, the hydration reaction changes the composition of the filling body and absorbs the water in the filling body, which makes the structure of the filling body dense and thus improves the strength of the filling body.
(4) in order to apply the phosphogypsum slag base early strong filling cementitious material to the Jinchuan mine, in view of the requirements of the Jinchuan mine filling system and the high concentration slurry pipeline transportation requirements, the test of the flow characteristic parameters of high concentration slurry of the phosphogypsum slag base early strong filling cementitious material and the study of the pipeline transportation characteristics have been carried out.
The results show that the fluidity of the filling slurry of the phosphogypsum slag base early strong cementitious material is basically the same as that of the cement filling slurry. The new type of early strong cementitious material filling slurry fully meets the liquidity requirement of the filling slurry in Jinchuan mine (consistency > 9cm, the collapse degree is more than 20cm, the delamination degree is less than 2.0cm). Under the condition of 78% and the ratio of cementing to 1:4, the early strong filling cementitious material slurry belongs to the Bingham fluid, which can be considered as an homogeneous fluid and presents a laminar flow in the pipeline transportation.
Using the test results of the flow characteristics of filling slurry, the FLUENT software is used to carry out numerical simulation analysis of the new type of early strong filling cementitious material slurry in pipeline. The change law of slurry flow velocity, flow core, pressure strength and friction resistance of high concentration filling slurry flow through straight pipe, bend pipe and long distance staircase pipeline is revealed. Using phosphogypsum slag base early strength filling cementitious material instead of cement, the industrial application of new filling cementitious material can be used in Jinchuan mine high concentration self flow filling system at present, so as to realize the safety, efficiency, green and economic exploitation of the deep resources of Jinchuan mine.

【学位授予单位】：北京科技大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TD853.34

【参考文献】