One of the two kilns there – Kiln No 2 – is 44 years old and has been out of service for more than a year due to the economic slowdown.
A spokeswoman for Cemex said: "This is indeed a major investment. While the demolishing of the old precipitator has now been completed, the new installation will not be finished until October time.
"The fabrication is currently taking place off-site. This new, state-of-the-art filter will not only comply with existing dust emissions legislation, but also future legislation."