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Although hydrofluoric acid is regarded as a weak acid, it is very corrosive, even attacking glass when hydrated. [ 20 ] Dilute solutions are weakly acidic with an acid ionization constant K a = 6.6 × 10 −4 (or p K a = 3.18 ), [ 10 ] in contrast to corresponding solutions of the other hydrogen halides, which are strong acids ( p K a < 0 ).
Hydrogen fluoride is typically produced by the reaction between sulfuric acid and pure grades of the mineral fluorite: [14] CaF 2 + H 2 SO 4 → 2 HF + CaSO 4. About 20% of manufactured HF is a byproduct of fertilizer production, which generates hexafluorosilicic acid. This acid can be degraded to release HF thermally and by hydrolysis: H 2 SiF ...
The typical hydrofluoric acid (HF) alkylation unit requires far less acid than a sulfuric acid unit to achieve the same volume of alkylate. The HF process only creates a small amount of organofluorine side products which are continuously removed from the reactor and the consumed HF is replenished.
The Torrance Refinery Action Alliance organized the rally and argued that safer alternatives exist, and that many of the refineries in California no longer use hydrofluoric acid.
In the early morning of June 21, 2019, a fire and multiple explosions occurred at the Philadelphia Energy Solutions (PES) refinery in Philadelphia, Pennsylvania.A release of hydrocarbons and hydrofluoric acid in the refinery's alkylation unit caused a ground-hugging vapor cloud which rapidly ignited, leading to three separate explosions minutes apart from each other.
This page contains tables of azeotrope data for various binary and ternary mixtures of solvents. The data include the composition of a mixture by weight (in binary azeotropes, when only one fraction is given, it is the fraction of the second component), the boiling point (b.p.) of a component, the boiling point of a mixture, and the specific gravity of the mixture.
The optional second step (for bare silicon wafers) is a short immersion in a 1:100 or 1:50 solution of aqueous HF (hydrofluoric acid) at 25 °C for about fifteen seconds, in order to remove the thin oxide layer and some fraction of ionic contaminants. If this step is performed without ultra high purity materials and ultra clean containers, it ...
Buffered oxide etch (BOE), also known as buffered HF or BHF, is a wet etchant used in microfabrication.It is a mixture of a buffering agent, such as ammonium fluoride NH 4 F, and hydrofluoric acid (HF).