Inside Ravensdown Napier’s $50m upgrade - and farewell to its red and white stacks

The Ravensdown plant near Napier. Pictured is the new stack (the large one on the right) and the three old stacks, which are set to go. Photo / Jaryd Louter

When Napier fertiliser plant Ravensdown roars back to life following a $50 million upgrade, it will feel like the business has finally “turned a corner” after surviving fire and flood.

The Awatoto site has been in a three-month shutdown period since June to undergo an upgrade and meet consent requirements for the next 35 years.

That includes erecting a new 55m-tall stack (chimney) and scrubber system to replace three old and smaller stacks - two of which are painted red and white and have become something of a local landmark off State Highway 51.

Those redundant stacks will be dropped in the coming weeks, if all goes to plan.

The upgrades have also seen a new converter installed, which is a giant structure for making sulphuric acid.

A separate project has been carried out during the shutdown period installing a new roof on the manufacture building, following damage from a fire in September 2022.

That fire, combined with serious flooding during Cyclone Gabrielle in February 2023, which shut down production for a matter of months, has meant a difficult few years for the company.

Ravensdown works manager Tony Gray said the current upgrades marked a milestone and the plant would be operational again by mid-September.

“We have turned a corner and broken the back of cyclone recovery work and the two major capital improvement works, so we are in a good position to ensure our future,” he said.

Ravensdown works manager Tony Gray (right) and contractor Mike Finlayson, from Artifex, inside the manufacture building. Photo / Gary Hamilton-Irvine

“We are committed to the region and wouldn’t be making this kind of investment unless we saw confidence in the site.”

Ravendsown is a co-operative owned by farmers and the business operates three plants in Napier, Christchurch and Dunedin.

The Napier plant employs about 60 people and is the company’s largest by far and also the largest fertiliser factory in the country.

Ravensdown did not shed any staff during the cyclone but went through a restructure earlier this year, including losing a “handful” of workers at its Napier plant.

It was announced last week that the company was considering stopping fertiliser production at its Dunedin plant.

‘Like baking a cake’

Gray explained the fertiliser process at Awatoto was “very much like baking a cake”.

The plant uses sulphur imported from Canada and delivered via Napier Port to make sulphuric acid.

A mountain of sulphur stored at Ravensdown. Photo / Gary Hamilton-Irvine

That acid is sent from the acid plant (at the southern end of the site) to the manufacture building, where it is mixed with phosphate rock, which is imported from “various countries” within Africa, Asia and Australasia.

“We grind that [phosphate rock] up into a flour or talcum powder-like consistency to increase the surface area and that enables the acid to react with the phosphate,” Gray said.

That mixture goes through a series of machines, including an oven, producing world-class fertiliser.

Gary Hamilton-Irvine is a Hawke’s Bay-based reporter who covers a range of news topics including business, councils, breaking news and cyclone recovery. He formerly worked at News Corp Australia.