Purification of metallic objects in the presence of a liquid and layer silicate(s)
This invention is related to a process for purification of metallic objects comprising an oil-adsorbing step in the presence of a liquid and a layer silicate component.
1 . Process for purification of metallic objects, comprising an oil-adsorbing step in which a composition containing:
a liquid and
a layer silicate component are applied to the metallic objects,
wherein
the process is performed in the absence of surfactants in the composition, and
the layer silicate component and the liquid have a ratio of from 0.05:1 to 0.6:1, based on weight, and the composition has a pH of from 4 to 10.6, the process is performed at a temperature of from 10° C. to 50° C., or both the composition has a pH of from 4 to 10.6 and the process is performed at a temperature of from 10° C. to 50° C.
2 . Process according to claim 1 wherein the liquid comprises water.
3 . Process according to claim 1 wherein the layer silicate component comprises montmorillonite.
4 . Process according to claim 1 wherein the process is performed in soak or barrel equipment, rotary drum washing equipment, sprinkler equipment and/or spray equipment.
5 . Process according to claim 1 wherein the process comprises one or more washing steps after the oil-adsorbing step.
6 . Process according to claim 5 wherein a slurry is at least partially transferred to the oil-adsorbing step.
7 . Process according to claim 1 , wherein the layer silicate component comprises silicon dioxide and aluminum dioxide, wherein in the layer silicate component the silicon dioxide and the aluminum dioxide amount together to 85 wt.-% or more, based on a total weight of the layer silicate component.
8 . Process according to claim 1 further comprising an abrasive step of applying an abrasive material to the metallic objects, wherein both steps are performed simultaneously.
9 . Process according to claim 8 , wherein the abrasive material comprises aluminum oxide.
10 . Process according to claim 8 , wherein the layer silicate component comprises aluminum dioxide.
11 . Process according to claim 8 , wherein
(1)—the layer silicate component has a total amount ranging from 10 wt.-% to 40 wt.-%, based on a combined total weight of the liquid, the layer silicate component, and the abrasive material, or
(2)—the abrasive material has a total amount ranging from 0.5 wt.-% to 15 wt.-%, based on the combined total weight of the liquid, the layer silicate component, and the abrasive material,
or both (1) and (2).
12 . Process according to claim 8 , wherein the abrasive material is provided in a slurry.
13 . Process according to claim 12 , wherein the slurry comprises at least partly the liquid utilized in the oil-adsorbing step.
14 . Process according to claim 1 wherein the metallic objects have an oxidic material thereon.