METHOD OF PREPARING CHROMIUM/COPPER/ARSENIC-TYPE ANTISEPTIC FOR IMPREGNATION OF WOOD Russian patent published in 2006 - IPC B27K3/28 B27K3/32 

FIELD: antiseptic production.

SUBSTANCE: invention, in particular, relates to production of antiseptic compositions for preserving wood and wood products from putrefaction and destruction by termites, fungi, and insects. Preparation of chromium/copper/arsenic-type antiseptic comprises preparing mother liquor followed by addition of chromium(VI) and copper(II) compounds and water to achieve predetermined arsenic/chromium/copper ratio, wherein mother liquor of arsenous acid is first prepared through reaction of arsenic(III) oxide or arsenic metal with 30-32% nitric acid at solids/liquid ratio 1:(2.0-3.0) while gradually raising temperature from 70-75°C to 95-100°C, after which chromium(VI) and/or copper(II) compounds as well as water are added to mother liquor immediately before use to achieve required arsenic/chromium/copper ratio = 1.0:(0.6-1.0):(0.3-0.8). Thus prepared antiseptic contains no free sulfuric acid and is convenient in storage and transportation, and capable of providing a wide range of components constituting it.

EFFECT: enabled processing of any type of wood products depending of the kind of wood and destination of products.

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