The Century Mine TSF is approximately 2.7km long (north-south) and 2.2km wide (east-west). The tailings resource in the northern end of the TSF is approximately 10m deep while the resource is approximately 22m deep in the south-eastern corner, with an average thickness of 13m.

The Century Zn-Pb-Ag deposit was discovered in 1990 by Rio Tinto Exploration Pty Ltd while drill testing a zinc, lead, silver soil geochemical anomaly. The deposit contained a resource estimate of 118Mt @ 10.2% Zn, 1.5% Pb & 36g/t Ag. The deposit was mined from 1999 to 2015, producing an average of 475,000tpa zinc concentrate and 50,000tpa lead concentrate.

Century Tailings Deposit
A single substantial tailings deposit exists at Century, generated from 16 years of large scale operations from the Century open pit.

Substantial recoverable zinc mineralisation exists in the tailings at Century, due to the historical focus on throughput maximisation as opposed to recovery maximisation. The nature of the original Century ore required extended flotation time and given the scale of the original Century deposit (105Mt at 12% Zn) a high throughput processing plant was constructed, achieving relatively modest recoveries (74% in 2015) over the life of operations.

Three independent metallurgical studies have been completed on the Century Tailings Deposit, demonstrating the tailings may be reprocessed through the existing plant on site with minor modifications to achieve recovery of >60% of remaining zinc mineralisation into a saleable ~52% zinc concentrate.

The simple reprocessing of the Century tailings provides a mechanism for the economic rehabilitation of the mine site, with the tailings area representing a significant portion of the current rehabilitation requirements. After reprocessing, the tailings are planned to be deposited back into the original open pit and encapsulated via subaqueous deposition.

In-situ
Deposits Beyond the significant tailings resource, three in-situ resources provide the ability to expand production or increase mine life beyond processing of tailings.  The total JORC compliant Indicated and Inferred Mineral Resources is 9.3Mt at 6.1% Zn, 4.7% Pb and 66g/t Ag for 568,000t contained zinc, 433,000t contained lead and 19,850,000oz contained silver.

Silver King Deposit
The Silver King lead-zinc-silver deposit is 1.5km SW of the original Century open pit.

Discovered in 1897, Silver King had a rich history of small scale mining until 1961, having been accessed by 15 shafts and associated underground workings to a depth of approximately 60m. Estimated historical production is 3,149t of lead and 100,000oz of silver. The Silver King mineralisation consists of a series of moderately to steeply dipping quartz-galena-sphalerite-siderite veins associated with a NE trending dextral strike-slip fault. Further sphalerite and galena mineralisation occurs within shale hosted breccia also associated with the veins.

Silver King provides further potential for an economic operation to be established on site utilising existing infrastructure. The Silver King Deposit was never mined by previous owners of Century largely due to its relatively small scale (and partial underground) nature compared with the Century open pit operations.

With the implementation of tailings reprocessing operations, potential exists to extract Silver King for utilisation as a blending ore.

South Block Deposit
The South Block deposit is located on teh southernmost portion of the original Century ore body and directly adjacent to the existing processing plant.

While South Block represents a continuation of the historical Big Zinc ore body, which was successfully mined and processed for over 16 years, New Century elected to complete metallurgical testwork on the drilling samples for confirmation of historical performance and potential areas of recovery optimistation.

East Fault Block Deposit
The East Fault Block is a small deposit located 35m below the surface of the run-of-mine stockpile area at the mine site and extends to a depth of 112m.

Phantom Hills Phosphate Deposit
The Century tenements host substantial phosphate mineralisation in the Phantom Hills Deposit and other minor deposits, located directly to the NE of the Century open pit. In 2013, a 14,300m RC and diamond drilling program was completed over the phosphate deposit area.

Despite the extensive drilling to date, a defined resource for the Phantom Hill Phosphate Deposit is yet to be estimated.

Conversion of the Century infrastructure to support a phosphate rock processing operation presents a low cost and low risk option to extending the life of Century operations and infrastructure beyond zinc and lead processing activities.

The Century Tailings Deposit is to be mined utilising the hydraulic mining method. At a capacity of 15Mtpa, this process will involve the use of five track mounted monitor units; four actively working individual faces throughout the Deposit and one on standby.

The Deposit will be mined in 8m deep benches which dip at 0.5% to the north and south sumps. Cuts will be done utilising a top down mining method at 18° utilising a 6m standoff from the monitor tracks to the edge of bench. The main production phase will mine the Deposit leaving a 300mm loss on the floor of the deposit while taking 100mm of dilution in the main production pass.

A separate clean-up crew will follow the production crew after a period of time, in order to remove the remaining contaminated material and an additional 100mm of dilution. This material will be mostly bypassed to the open pit void as waste. This clean up forms part of the final rehabilitation process for the TSF area.

The mine design has two sumps, which provides greater flexibility in the mine plan, and reduces the risk of significant downtime during heavy rain events.

Tailings slurry from hydraulic mining will be passed over a trash screens before being sent to a feed thickener. The purpose of the feed thickener is to ensure consistent density and flow rate into the Century Processing Plant. The Plant will have sufficient surge capacity for 2 hours of production to further assist in smoothing production.

Thickened slurry is sent to the classification circuit (cyclones) where the +53µm size fraction will be sent to one of the existing ball mills in an open circuit arrangement.

Milled material will be combined with cyclone overflow and sent to one of two parallel flotation circuits. The flotation circuit consists of rougher, scavenger and cleaner circuits in each train. Regrind mills are used on cleaner 1 concentrates to improve recovery of zinc.

The final zinc concentrate is thickened and pumped to concentrate storage tanks prior to being pumped to the Karumba Port facility via the underground slurry pipeline. ........