Hydration of dicalcium silicate and diffusion through neo-formed calcium-silicate-hydrates at weathered surfaces control the long-term leaching behaviour of basic oxygen furnace (BOF) steelmaking slag

Alkalinity generation and toxic trace metal (such as vanadium) leaching from basic oxygen furnace (BOF) steel slag particles must be properly understood and managed by pre-conditioning if beneficial reuse of slag is to be maximised. Water leaching under aerated conditions was investigated using fresh BOF slag at three different particle sizes (0.5–1.0, 2–5 and 10 × 10 × 20 mm blocks) and a 6-month pre-weathered block. There were several distinct leaching stages observed over time associated with different phases controlling the solution chemistry: (1) free-lime (CaO) dissolution (days 0–2); (2) dicalcium silicate (Ca₂SiO₄) dissolution (days 2–14) and (3) Ca–Si–H and CaCO₃ formation and subsequent dissolution (days 14–73). Experiments with the smallest size fraction resulted in the highest Ca, Si and V concentrations, highlighting the role of surface area in controlling initial leaching. After ~2 weeks, the solution Ca/Si ratio (0.7–0.9) evolved to equal those found within a Ca–Si–H phase that replaced dicalcium silicate and free-lime phases in a 30- to 150-μm altered surface region. V release was a two-stage process; initially, V was released by dicalcium silicate dissolution, but V also isomorphically substituted for Si into the neo-formed Ca–Si–H in the alteration zone. Therefore, on longer timescales, the release of V to solution was primarily controlled by considerably slower Ca–Si–H dissolution rates, which decreased the rate of V release by an order of magnitude. Overall, the results indicate that the BOF slag leaching mechanism evolves from a situation initially dominated by rapid hydration and dissolution of primary dicalcium silicate/free-lime phases, to a slow diffusion limited process controlled by the solubility of secondary Ca–Si–H and CaCO₃ phases that replace and cover more reactive primary slag phases at particle surfaces

Watershed Supply Assessment for Kaskaskia River Watershed Development: Phase I Technical Report

This document was prepared for the Kaskaskia Basin Water Supply Planning Committee to aid their development of a plan for meeting the future growth of water supply demands within the basin. It contains background information to provide an overview of management criteria and an understanding of the constraints and policies used in conducting analyses and making decisions concerning water use within the Kaskaskia Basin. This report describes the following work of the Illinois State Water Survey, funded by the Illinois Clean Coal Institute: Retrieval and summation of existing information regarding surface water and groundwater availability in the region. This report of existing information will also include information provided by the Illinois Department of Natural Resources-Office of Water Resources (IDNR-OWR) addressing the water supply storage and allocations from Carlyle Lake and Lake Shelbyville. Development of surface and groundwater hydrologic models to simulate the hydrology of the Kaskaskia River watershed, water levels in the federal reservoirs, and selected local groundwater resources. Specific models developed include: a Streamflow Accounting Model, a Watershed Simulation Model and Reservoir Routing Models, and a set of Groundwater Flow Models. Major portions of this report deal with a summary of existing information. The models developed in this study will be applied to water use planning scenarios in the ongoing Phase II effort funded by the IDNR-OWR. Only limited results are available for inclusion in this report.published or submitted for publicationis peer reviewe

Water Supply Assessment for Kaskaskia River Watershed Development: Phase 1 Technical Report

published or submitted for publicationis peer reviewe

RRP1B Targets PP1 to Mammalian Cell Nucleoli and Is Associated with Pre-60S Ribosomal Subunits

Protein phosphatase 1 (PP1) accumulates within the nucleolus, which plays a central role in regulation of cell growth and proliferation. Using a powerful combination of imaging and quantitative proteomics, we identify RRP1B as a nucleolar PP1 targeting subunit that sits at the hub of the pre-60S ribosomal subunit processing complex