江汉盆地西南缘南湖峪矿区石盐矿水溶性能试验研究

Experimental Study on the Water-Solubility Properties of Rock Salt Deposits in the Nanhuyu Mining Area, Southwestern Margin of the Jianghan Basin

摘要: 南湖峪矿区石盐矿层赋存于古近系新沟嘴组含盐岩段，首采层K1 (III、IV、V盐层合并)纯盐平均真厚8.62 m、NaCl平均品位79%。依据DZ/T 0212.3-2020，对ZK1002钻孔16组(32件)试样进行水溶性能试验。结果表明：溶蚀速度随卤水浓度升高而下降；低浓度下上溶速度明显高于侧溶，侧溶达饱和平均46.7 h，快于上溶的59.3 h；饱和卤水膨胀率平均11.39%，产1 m³饱和卤水耗淡水约0.90 m³；残渣膨胀率仅0.05%~0.18%；饱和卤水以NaCl为主(298~340 g/L)，品质纯。矿石溶解性能良好，适宜钻井水溶法开采，成果可为水溶开采设计与盐穴选划提供基础数据。

Abstract: The rock salt seams in the Nanhuyu mining area occur in the salt-bearing member of the Paleogene Xingou Formation. The primary mining horizon K1 (merged from seams III, IV and V) has an average pure-salt thickness of 8.62 m and an average NaCl grade of 79%. According to DZ/T 0212.3-2020, water-solubility tests were carried out on 16 groups (32 specimens) from borehole ZK1002. The results show that the dissolution rate decreases with rising brine concentration; at low concentrations the top dissolution rate is clearly higher than the lateral one. The lateral brine reaches saturation in 46.7 h on average, faster than the top test (59.3 h). The saturated brine has an average expansion ratio of 11.39%, i.e. about 0.90 m³ of fresh water is consumed per 1 m³ of saturated brine. The residue expansion ratio is only 0.05%~0.18%. The saturated brine is dominated by NaCl (298~340 g/L) and is of high purity. The ore has good solution properties and is suitable for drilling solution mining. The results provide basic data for solution mining design and salt cavern siting.