A method includes: (1) using a chelating agent, extracting divalent ions from a brine solution as complexes of the chelating agent and the divalent ions; (2) using a weak acid, regenerating the chelating agent and producing a divalent ion salt solution; and (3) introducing carbon dioxide to the divalent ion salt solution to induce precipitation of the divalent ions as a carbonate salt. Another method includes: (1) combining water with carbon dioxide to produce a carbon dioxide solution; (2) introducing an ion exchanger to the carbon dioxide solution to induce exchange of alkali metal cations included in the ion exchanger with protons included in the carbon dioxide solution and to produce a bicarbonate salt solution of the alkali metal cations; and (3) introducing a brine solution to the bicarbonate salt solution to induce precipitation of divalent ions from the brine solution as a carbonate salt.

Systems and methods for impurity removal to limestone using modifications to the typical calcination process of turning calcium carbonate into calcium oxide. Specifically, substantially increasing the temperature to 1100° C. or higher and increasing soak time can result in reductions in certain undesirable impurities, particularly with regards to lead and lead compounds.

Integrated refinery processes and systems for generating hydrogen by direct decomposition of hydrocarbons. The integrated processes and systems can be used to capture carbon and sulfur in solid form, reducing carbon dioxide and sulfur oxide emissions. The processes include reacting sour gas with a metal-based sorbent in a reactor to produce sulfur-bearing solids and water, and to partially reform hydrocarbons in the sour gas to produce hydrogen-rich syngas; and cracking remaining hydrocarbons thermally with or without the presence of a catalyst to produce hydrogen and solid carbon.

Disclosed is a ceramic composition comprising a plurality of at least semi-coherent particles with an average diameter ranging from 1 nm to 50 nm included within a matrix, wherein the matrix comprises one metal carbonate salt, metal oxide or metalloid oxide, the particles and the matrix share at least one metal element and the metal element is 10% to 80% of the total content of said matrix, and the composition has a lattice mismatch of less than 5%. Disclosed are also an article and methods for making the ceramic composition of the present invention.

The present invention relates to a process for decomposing calcium sulfate (CaSO.sub.4) present in phosphogypsum (PG), comprising the following steps: a) providing a reactor containing phosphogypsum (PG) and a solid source of carbon (C), b) reacting a flow of dioxygen (Oz) with the source of carbon (C) so as to generate carbon oxide (CO), c) reacting carbon oxide (CO) obtained in step a) with calcium sulfate (CaSO.sub.4) of the phosphogypsum to produce calcium oxide (CaO) and sulfoxide (SO.sub.2) according to the following reaction: CaSO.sub.4+CO.fwdarw.CaO+SO.sub.2+CO.sub.2 wherein the mass ratio C/PG is between 0.2 and DA, and the mass ratio 15 O.sub.2/PG is between 0.5 and 1.5.

The present invention provides methods for mineral precipitation and/or cementation of permeable or fractured non-porous materials using isolated urease.

The present invention provides methods for mineral precipitation and/or cementation of permeable or fractured non-porous materials using isolated urease.

Disclosed is a ceramic composition comprising a plurality of at least semi-coherent particles with an average diameter ranging from 1 nm to 50 nm included within a matrix, wherein the matrix comprises one metal carbonate salt, metal oxide or metalloid oxide, the particles and the matrix share at least one metal element and the metal element is 10% to 80% of the total content of said matrix, and the composition has a lattice mismatch of less than 5%. Disclosed are also an article and methods for making the ceramic composition of the present invention.

The present invention relates to calcium hydroxide particles having a total pore volume greater than 0.18 cm.sup.3/g, said total pore volume being calculated with the BJH method for a range of pores having a diameter of between 20 and 1000 Å, said particles being characterized in that the BJH partial pore volume for the range of pores having a diameter of between 20 and 100 Å corresponds to more than 20% of said BJH total pore volume.

Disclosed herein are embodiments of composite hexagonal ferrite materials formed from a combination of Y phase and Z phase hexagonal ferrite materials. Advantageously, embodiments of the material can have a high resonant frequency as well as a high permeability. In some embodiments, the materials can be useful for magnetodielectric antennas.