Study on Properties and Microstructure of a New Filling Cementing Material in a Polymetallic Mine
By using slag new cementing material as cementing agent and fine tailing sand as aggre-gate,tests on fluidity,bleeding rate and filling ratio of filling slurry were carried out to study the effects of concentration,lime sand ratio on slurry fluidity,bleeding rate and compressive strength of backfill,as well as the development law of compressive strength of backfill under different curing ages.The results show that filling concentration has great influence on slurry flow and bleeding rate,and with the increase of concentra-tion,slurry flow and bleeding rate decrease significantly.The influence of lime sand ratio is relatively small.With the decrease of lime sand ratio,slurry fluidity and bleeding rate increase slightly.The compressive strength of the backfill increases with the increase of the concentration and decreases with the decrease of the ratio of lime to sand.The strength of the new cementified material backfill develops slowly at the early stage of curing for 3 d,the strength begins to increase significantly after 7 d,and the strength continues to increase after 28 d,and the strength at 60 d of curing is increased by about 20%compared with 28 d.The hydration products such as fibrous C-S-H and needle-rod ettringite formed by the slag fine powder under the excitation of cement and gypsum are the main reasons for the strength of the backfill.
new filling cementing materialfluiditybleeding ratestrengthcementation mechanism
NETL
NSTL
万方数据
维普
