An exploratory study of acetate decomposition and dissolution of quartz and Pb-rich potassium feldspar at 150°C, 50 MPa (500 bars)

Author:

Manning D. A. C.,Rae E. I. C.,Small J. S.

Abstract

AbstractExperiments to explore the dissolution behaviour of Pb-rich orthoclase (1% PbO) and quartz have been carried out in the presence of pH buffered and unbuffered potassium acetate and lithium acetate solutions at 150°C and 50 MPa (500 bars). In pH-unbuffered potassium acetate solutions Pb and Na solubilities (and pH) increase with increasing fluid acetate content, reflecting increased bulk dissolution of the feldspar; silica solubility decreases despite an increase in measured pH from 7.5 to 8.9. Similarly, in experiments at pH 6 using a potassium acetate pH buffer, quartz solubility decreases with increasing acetate content. The use of lithium acetate pH buffers (pH 6 at 25°C) in experiments with orthoclase plus quartz results in the precipitation of the lithium chlorite cookeite, complicating interpretation of the fluid chemistry. It is also apparent that in the presence of orthoclase plus quartz (but not albite alone) acetate decarboxylation takes place at much higher rates than expected for the experimental configuration used. The observed effects are unlikely to be due to the presence of acetate alone; the influence of species produced by acetate decay (especially carbonate) must also be considered. This study provides little support for models which call upon acetate to enhance the solubility of aluminosilicate minerals, and suggests that acetate decarboxylation in nature may limit its involvement in dissolution processes. It emphasises the potential of feldspars as sources of elements for mineralisation, such as Pb.

Publisher

Mineralogical Society

Subject

Geochemistry and Petrology

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3