Purification of metallic objects in the presence of a liquid and layer silicate(s)

Abstract

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.

Claims

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.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) FIG. 1 demonstrates the effect as described in Example 1

(2) FIG. 2 shows an example for an embodiment of the inventive process (1): mixture of liquid/layer silicate component (2): loading (for metallic objects) (3): Rotary drum washing equipment (4): removal (of metallic objects) (5): agitation (here: air bubbling) (6): sprayer (for abrasive step) (7): transfer line for mixture of liquid/layer silicate component to sprayer (6)

(3) FIG. 3 shows an example for the embodiment of the inventive process according to FIG. 1 with subsequent washing steps

EXAMPLE

Example 1: Oil Adsorption Capacity

(4) According to the following table, mixtures of 5 g clay (W05-25 Sibelco), 20 g water and different amounts of oil (15W-40 motor oil) were prepared (samples 1a to 1e). The lid was closed and then the mixture was thoroughly shaken manually for 10 minutes. The mixture was allowed to settle. Pictures were taken. These can be found in FIG. 1. In all cases only one liquid phase was yielded.

(5) TABLE-US-00001 Relative Number of amount of liquid Sample Clay Water Oil oil:clay phases 1a 5 g 20 g 0 g 0% 1 1b 5 g 20 g 1.25 g 25% 1 1c 5 g 20 g 2.50 g 50% 1 1d 5 g 20 g 3.75 g 75% 1 1e 5 g 20 g 5.00 g 100% 1