The plant was mothballed in 2009 during the recession, but a continuing upturn in construction activity prompted Hanson to return to the site and prepare it for re-opening.
It takes blast furnace slag, a by-product of the steel industry, and grinds it into a fine powder for use as a cement substitute in ready-mixed concrete. The raw material was originally sourced from the nearby steel works, which has now closed. In future it will be imported, helping to sustain the docks.
Site manager Duncan Felgate said: "It has taken nine months to get up and running again. One of the main problems we had to overcome was to replace all the copper wiring, which had been meticulously stripped out by thieves."
The £2m project to re-open the site was completed on time and on budget and the new staff have all been put through a comprehensive technical and operational training programme.
Some of them have returned to Hanson having been at the works before it was mothballed, but the majority are new starters.
Hanson sells its ground granulated blast furnace slag under the Regen brand name and operates a further two UK production plants at Purfleet in Essex and Port Talbot in south Wales.
Regen is in particularly high demand as a sustainable alternative to cement in ready-mixed and precast concrete. Replacing one tonne of cement in concrete with Regen reduces the embodied CO2 by around 900kg, and also increases its durability. It is added at the mixing plant and can replace as much as 90 per cent of the cement content.
Hanson UK, part of the HeidelbergCementGroup, is split into four business lines – aggregates, concrete, asphalt and contracting and cement. Together these operate over 300 manufacturing sites and employ more than 3,500 people.