Mining in Goa

     Mining for iron ore in Goa is carried out in the following phases: 

 Exploration and development

Large expanses of land are scanned using technologies such as satellite imaging, geological exploration and developmental mapping, geo-mechanical and superficial geological sampling. 

A more in-depth exploration is carried out in areas that demonstrate evidence of mineral ore deposits. This stage of exploration comprises drilling, digging of trenches, etc, to ensure accuracy of data and confirm the feasibility of exploration.  

Once the location and presence of iron ore deposits has been pinpointed, the project goes into planning and development. The major activities in this stage include mine planning and installation, construction of infrastructure and the setting up of processing & upgradation facilities. 

 

Extraction of Iron Ore

Iron ore extraction in Goa in done through the surface by open pit mining.

 

Open Pit Mining

Open-pit mining is considered to be more economical and safer than underground mining, especially when the ore body is large and there is a significant amount of overburden. Additionally, the advent of large earth moving equipment, less expensive energy sources, and improved extraction and beneficiation technologies, has increased the viability of this method.  This method is particularly advantageous in the Goan context as its lower cost enables the economically effective exploitation of lower-grade ores. 

A large number of Goa’s open pit mines operate below ground water level. The ground is cut into systematic benches with bench height and width being maintained at approximately seven metres. Deeper ore is progressively accessed by laterally extending pits in all directions while generally maintaining an overall slope of 30 degrees. 

The lateritic overburden and mining lumpy ore zone are removed, revealing the powdery ore zone below. On an average, ~ 2 to 3 tonnes of overburden material (comprising laterite, lateritic clay, manganiferous clay and phyllites) have to be extracted to yield one tonne of powdery ore. The overburden material is dumped in designated areas while the ore is taken for processing. 

 

Processing

Goan iron ore is transported to the milling and beneficiation plants where it goes through processes like crushing, washing, sorting, sizing, magnetic separation, flotation, and other means of gravity separation. This removes unwanted constituents from the ore and concentrates the valuable metal, improving its quality, purity or grade. 

Most Goan iron ore mines are partially or fully mechanised. The mining companies have set up dry screening facilities at the mines and wet beneficiation plants at the mines or near loading points.  

 

Transportation & Shipping

 

Transportation: 

Processed iron ore is transported to waiting ships over land and water. 

 

Trucks

The mined ore and overburden is transported from various mining leases to a jetty by haulage trucks over distances ranging from 1 to 20 km.

 

Barges

Iron ore is transported on barges via the Mandovi and Zuari rivers, their tributaries and the Cumbarjua Canal, the combined navigable length of which is about 65 km. A number of loading stations have been constructed along this route. Barges are loaded either by conveyer systems or by rear-dump trucks that dump ore directly from barge-loading jetties. 

 

Loading & Shipping:

Loading and shipping is done at the Mormugao and Panjim ports by transhippers and floating cranes. 

Mormugao Port 

Panamax size vessels are loaded at Berth no. 9 of Mormugao Port at the rate of 45,000 tonnes per day (TPD). Large cape-sized vessels are also loaded up to a draft of 14.0 metres and are thereafter topped up utilising transhippers. 

Panaji Port 

Loading at Panaji Port is done using transhippers, floating cranes and self-unloading barges. The loading capacity is approximately 60,000 to 70,000 TPD and has helped reduce the congestion at Mormugao Port. 

Transhippers

Transhippers are an offshore loading facility that can load vessels of any size without any draft limitations. They complement the loading facilities at the dedicated berth for iron ore by uptopping vessels.  Transhippers enable the loading of vessels of more than 200,000 DWT and have an average output of around 15,000 ~ 25,000 TPD/ transhipper. Currently, there are six transhippers operating within the port limits of Mormugao and Panaji ports, namely:

(a)Maratha Deep 

(b) Priyamvada 

(c) Sunrise 

(d) Orissa 

(e) Satixsha

(f) Goan Pride

Floating Cranes

A floating crane consists of a jib crane fitted on self-propelled pontoons. Complete with accommodation, generators, mooring/anchoring systems, fire fighting & life saving equipment, navigation systems, etc, they conform to all the latest technical specifications. Currently there are three such floating cranes operating within the minor port limits. They are the M.V. Dona Paula, M.V. Maria Laura & M.V. Miramar.

Weather permitting, floating cranes are capable of loading bulk materials in excess of 20,000 TPD from barges to mother vessels ranging from Handy Max to Super cape sizes. They can also be used to unload bulk materials from Super cape sizes to Handy size into barges between 12,000 to 18,000 TPD. The three cranes can operate simultaneously on a cape vessel.