The utilization of geothermal energy remains underdeveloped, mainly due to the technical problem of silica scaling. The scaling can eventually disrupt the electricity production process due to frequent pipe maintenance. Although inevitable, scaling can be controlled by accelerating the precipitation process through the addition of silica seeds. Silica gel has an affinity to bind with dissolved silica in geothermal brine that therefore reduces the likelihood of silica to form scale on the pipeline surfaces. In the present work, brine was taken from geothermal well Unit 3A–3B at the Dieng geothermal power plant with an initial silica monomer concentration of approximately 420 ppm. Silica gel seeds were added to the brine at a precise pH and temperature and dissolved silica concentration was analyzed by detecting silica monomers with UV–visible spectrophotometry using the vanadate/molybdate (yellow) method. Experimental results showed that the silica concentration in the liquid phase could be reduced by the addition of these seeds. Silica precipitation was determined by mass transfer of silica monomers from the fluid phase onto solid surfaces, and it was found that precipitation decreased as pH and temperature increased. Calculations also showed that the mass transfer coefficient was enhanced by fluid agitation. The silica precipitation process was optimal at a pH of 7, a temperature of 40 °C and agitation speed of 800 rpm; the result was a mass transfer coefficient of 0.5924 cm/s. In a dimensionless correlation, the mass transfer coefficient can be expressed in the equation (kc·dp/DAB) = 1.4242·Re0.529·Sc0.3333.

中文翻译：

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添加种子的地热盐水中二氧化硅沉淀的动力学：在冷重注入系统中使二氧化硅结垢最小

地热能的利用仍然不发达，这主要是由于二氧化硅结垢的技术问题。由于频繁的管道维护，结垢最终会中断电力生产过程。尽管不可避免，但可以通过添加二氧化硅种子来加速沉淀过程来控制结垢。硅胶具有与溶解在地热盐水中的二氧化硅结合的亲和力，因此降低了二氧化硅在管道表面形成水垢的可能性。在目前的工作中，盐水是从Dieng地热发电厂的3A–3B地热井中抽出的，初始二氧化硅单体浓度约为420 ppm。在精确的pH和温度下将硅胶种子添加到盐水中，并使用钒酸盐/钼酸盐（黄色）方法通过紫外可见分光光度法检测二氧化硅单体来分析溶解的二氧化硅浓度。实验结果表明，通过添加这些晶种可以降低液相中二氧化硅的浓度。二氧化硅沉淀是通过将二氧化硅单体从液相传质到固体表面来确定的，发现随着pH和温度的升高，沉淀减少。计算还表明，流体搅拌可提高传质系数。二氧化硅沉淀过程的最佳pH值为7，温度为40°C，搅拌速度为800 rpm；结果是传质系数为0.5924 cm / s。在无量纲相关中