| # | Country | Total Patents | |
|---|---|---|---|
| #1 | Germany | 4 | |
| #2 | France | 4 | |
| #3 | Spain | 3 | |
| #4 | United Kingdom | 1 |
| # | Industry | |
|---|---|---|
| #1 | Materials and metallurgy | |
| #2 | Environmental technology | |
| #3 | Chemical engineering | |
| #4 | Thermal processes | |
| #5 | Basic materials chemistry |
| Publication | Filing date | Title |
|---|---|---|
| GB209020A | Improvements in rotary drum apparatus for cooling ores and other materials | |
| DE396896C | Manufacture of fine copper from copper oxide | |
| DE381204C | Process for the treatment of copper ores |