School of Environmental Sciences , University of Hull , Hull HU6 7RX , United Kingdom.
Chemical and Biological Engineering , University of Sheffield , Sheffield S10 2TN , United Kingdom.
Environ Sci Technol. 2018 Jul 17;52(14):7892-7900. doi: 10.1021/acs.est.8b01883. Epub 2018 Jul 3.
Carbonate formation in waste from the steel industry could constitute a nontrivial proportion of the global requirements for removing carbon dioxide from the atmosphere at a potentially low cost. To utilize this potential, we examined atmospheric carbon dioxide sequestration in a >20 million ton legacy slag deposit in northern England, United Kingdom. Carbonates formed from the drainage water of the heap had stable carbon and oxygen isotope values between -12 and -25 ‰ and -5 and -18 ‰ for δC and δO, respectively, suggesting atmospheric carbon dioxide sequestration in high-pH solutions. From the analyses of solution saturation states, we estimate that between 280 and 2900 tons of CO have precipitated from the drainage waters. However, by combining a 37 year long data set of the drainage water chemistry with geospatial analysis, we estimate that <1% of the maximum carbon-capture potential of the deposit may have been realized. This implies that uncontrolled deposition of slag is insufficient to maximize carbon sequestration, and there may be considerable quantities of unreacted legacy deposits available for atmospheric carbon sequestration.
钢铁工业废物中的碳酸盐形成，可能在低成本条件下构成全球从大气中去除二氧化碳需求的相当大的一部分。为了利用这一潜力，我们研究了英国北部一个超过 2000 万吨的遗留矿渣堆积地的大气二氧化碳封存情况。堆浸水中形成的碳酸盐具有稳定的碳和氧同位素值，δC 值在-12 到-25‰之间，δO 值在-5 到-18‰之间，表明在高 pH 值溶液中存在大气二氧化碳封存。通过对溶液饱和度状态的分析，我们估计从浸出水中已经沉淀了 280 到 2900 吨的 CO。然而，通过将长达 37 年的浸出水电化学数据集与地理空间分析相结合，我们估计该矿渣堆积地的最大碳捕获潜力可能仅实现了不到 1%。这意味着，未经控制的矿渣沉积不足以实现最大的碳封存，可能有相当数量的未反应的遗留矿渣可用于大气碳封存。
