| December, 2021 | Obtained the license of recycle EPA incinerator fly ash (medical waste treatment facility). (83 tons/month) |
| November, 2021 | Won 2021 Taiwan Circular Economy Excellent Enterprise Two Stars Award. (highest level) |
| November, 2021 | Obtained the experiment license of recycle electroplating sludge, led and the led compound, and inorganic sludge(zinc-contained sludge) from Ministry of Economic Affairs. (550 tons) |
| August, 2021 | Obtained the license of recycle general waste from Taoyuan EPB Xinrong BOO incinerator. (19,000 tons) |
| May, , 2021 | Obtained the license of recycle 15-40% zinc-contained product from recycle plant or treatment facility. (4000 tons/year) |
| February, 2021 | Obtained the tender of Taoyuan incinerator washed fly ash recycle plan. (amount: 9,400 tons/year) |
| January, 2021 | Obtained the finalized EPA Official Letter, titled "The Second Environmental Impact Difference Analysis Report of the Environmental Impact Statement of EAF Dust Resource Recycling Site Establishment Modification Program" for reference, added 3 categories for total 12 additional waste resources. |
| Obtained the license for reusing of EAF Dust(code: A-7101) from other electric arc furnace( including carbon steel and stainless steel electric arc furnace) and illegal dumping site in Taiwan. | |
| December, 2020 | Treated 1,644 metric tons of the EAF dust dumped illegally in Dadu Riverside, Zhanghua County free of charge. |
| November, 2020 | Won the Sustainable Individual Performance at the 13th Taiwan Corporate Sustainability Awards (TCSA) -Circular Economy Leadership Award and the Gold Award of the Corporate Sustainability Reports Award. |
| April, 2020 | Treated 6,397 metric tons of the EAF dust dumped illegally in Xinfeng Township, Hsinchu County free of charge |
| December, 2019 | Treated 7,258 metric tons of the EAF dust dumped illegally in Xinfeng Township, Hsinchu County free of charge |
| August, 2019 | Won the 5th Taiwan Mittelstand Awards from Minister of Economic Affairs. |
| February, 2019 | The total volume of EAF dust treated since June 1999 has reached two million tons. |
| December, 2018 | Treated 1,464.31 metric tons of the EAF dust dumped illegally in Xinfeng Township, Hsinchu County free of charge |
| January, 2018 | The Company's stock was listed on the Taiwan Stock Exchange for trading. |
| December, 2017 | Obtained the general permit for reuse of EAF dust from the Industrial Development Bureau, Ministry of Economic Affairs. |
| February, 2016 | Obtained the general permit for reuse of the contaminated soils from the EPA. |
| December, 2015 | Obtained the ISO 9001 certificate. |
| The annual capacity of the second rotary kiln for treating dust reached the maximum capacity 109,900 metric tons. | |
| Technology improving and upgrade completed, Significantly increase production capacity. | |
| August, 2015 | Obtained ISO14064 assurance statement. |
| December, 2014 | The annual capacity of the first rotary kiln for treating EAF dust reached the maximum capacity 89,000 metric tons. |
| July, 2014 | Obtained OHSAS18001 certificate. |
| December, 2013 | The volume of EAF dust treated by the second rotary kiln reached 100,000 tons the original design capacity. |
| March, 2013 | The total volume of EAF dust treated since June 1999 has reached one million tons. |
| December, 2012 | The annual capacity of the first rotary kiln for treating EAF dust reached 86,932 metric tons. |
| December, 2010 | Technology transfer to newly build EAF dust recycle plant of VMZ Group in Brazil |
| June, 2010 | Completed the second rotary kiln, began test run and operate formally. |
| January, 2007 | Obtained the ISO14001 environmental management system certification of the British Standards Institution (BSI). |
| July, 2004 | The annual processing capacity for EAF dust (wet basis) exceeded 60,000 metric tons. |
| December, 2003 | The annual processing capacity for EAF dust (wet basis) exceeded 50,000 metric tons, reached the original design capacity. |
| December, 2001 | Obtained a license for joint clearance and treatment of the business waste EAF Dust from the Ministry of Economic Affairs. |
| February, 2000 | Obtained the factory registration certificate from the Ministry of Economic Affairs. |
| August, 1999 | Approved by extraordinary general meeting Mid-North part Environmental Engineering Co., Ltd. and south area Industrial Co., Ltd. merged and change the name into Taiwan Steel Union Co., Ltd. |
| June, 1999 | The Company first rotary kiln began test run and operate formally. |
| December, 1996 | The Industrial Development Bureau, Ministry of Economic Affairs, approved the establishment of a joint treatment system for EAF dust and waste. |
| May, 1995 | Mid-North part Environmental Engineering Co., Ltd. was formally established. |
