Have you picked a contractor for unearthing the quantities needed for surveys?

Yes, we're partnered with engineering firm Steiger, which is among Estonia's best-known drilling companies. We will be drilling smaller and larger boreholes. With the latter, Steiger will in turn partner with Keller – an international company with German roots and one with a wealth of experience when it comes to more substantial boreholes.

When will drilling start?

We are in the planning phase and aim to start drilling in the Aru-Lõuna quarry this week.

We will drill six so-called ordinary boreholes first, with a diameter of around 10 centimeters, similar to the ones you drill for driven wells.

Three will be test holes to determine the depth at which phosphate rock can be found there.

The other three will be hydrogeological boreholes for groundwater testing equipment we'll use to monitor the properties of groundwater over a longer period of time.

After that, in early November, based on current plans, we'll drill seven larger boreholes with a diameter of around 1.2 meters.

This work will take around a month. After that, the boreholes will be closed and the area put in order. Only the holes necessary for hydrogeological surveys will stay open.

How deep will the test holes be?

We are talking about depths of up to 30 meters, so quite shallow, geologically speaking. For example, the holes we drill for geothermal energy can go down as deep as 500 meters.

Are the smaller and larger boreholes connected in that the former will help you judge where to drill the latter?

They are not directly linked. The smaller boreholes will tell us the exact locations of layers of different mineral resources in the area, but what we want to know more specifically can be garnered from the larger ones.

How much phosphorite will be unearthed?

We will be pulling around 25 metric tons of phosphate rock from the larger boreholes, next to a couple of tons of graptolitic argillite and glauconitic sandstone that lies above it. In simpler terms, we're talking about two or three truckloads.

There has been talk of 50 tons.

Our survey permit is for a maximum of 50 tons, but according to our best knowledge today, we will not need such a large quantity for our surveys. We will be limiting ourselves to around 30 metric tons.

How big is the drilling area?

Our survey focuses on a part of the Toolse phosphate rock bed – an extension of the Aru-Lõuna section for around ten square kilometers. The boreholes for samples will be drilled in an area of roughly 1,000 square meters.

How much risk is there for groundwater?

We are closely monitoring all potential risks. When it comes to phosphate rock and other critical raw material surveys, groundwater is among the most burning questions. One important focus of the survey is whether mining and processing would have an effect on groundwater.

The test drillings do not pose a threat to groundwater. Such smaller boreholes are frequently drilled for driven wells and are nothing special.

There have been larger boreholes, with a diameter of 1.2 meters, in Estonia before. For example, for the stakes supporting tall apartment buildings in Õismäe and Astangu. And there have been deeper ones than what we have planned for Aru-Lõuna. These have also passed through layers of groundwater while causing no damage.

During the spring awareness campaign, it was suggested that representatives of local government and communities will be able to keep an eye on the work if they so wish. Does this plan stand?

We met with the heads of Rakvere and Viru-Nigula municipalities last week. The information about drilling went up on both municipalities' websites and social media pages. Local media publications, including the Virumaa Teataja newspaper and Lääne-Viru Uudised news portal, have also covered this topic.

We are planning a single visitor day for the work to drill the larger boreholes. We're yet to pick a date, but the information will be made available.

It needs to be kept in mind that the work is being done in the territory of an operational limestone quarry, and there are safety measures that need to be taken by those who wish to visit us.

Once the sufficient quantity has been unearthed, what happens next?

The material will be packaged and transported to our Arbavere research center. Because the survey project runs from early 2023 to the end of 2025, the next stage will be testing the material more thoroughly than what universities usually do for their purposes. In other words, we will be running technological experiments to determine how phosphorite can be processed, as well as the chances of extracting rare earth metals from it.

Have you found a partner for this stage?

We have not yet picked a company to run those experiments, but we will have to look to foreign laboratories as there is no such competency in Estonia.

We would like to have clarity and pick a partner in the next month. We are waiting for final bids from two laboratories as thing stands.

Does this mean a part of the unearthed material will be taken abroad to be studied?

Indeed it does.

Will we know what will happen with the material once it's unearthed?

Once we have the phosphate rock, we will bring it to our center in Arbavere. By then, we would also like to know which laboratory will be handling the material and how much of it.

However, finding the laboratory partner and drilling the boreholes in Aru-Lõuna are not directly linked. We will still be moving the material to Arbavere even if we haven't found a contractor by then.

Will the geological service be able to study the cores from the smaller boreholes under its own steam?

We know what's in there based on previous surveys. The aim of these new drillings is to determine where exactly different strata begin and end. That much we can determine ourselves, and the cores will be kept at Arbavere.

What else will the surveys be looking at, in addition to the value of phosphate rock?

In terms of mineral resource processing and ongoing phosphate rock and other critical material surveys, phosphate rock holds rare earth metals, such as neodymium, which is used in wind turbines. Our goal is to determine how they could be extracted from phosphorite.

Our focus is also on the layer of graptolitic argillite. It contains vanadium, which is another critical raw material for the green transition. Graptolitic argillite also contains uranium.

We will also be studying glauconitic sandstone that in turn lays on top of graptolitic argillite, as it contains potassium.

What we want to know is how these metals could be extracted and whether it would make economic sense. There is no clear answer to those questions today.

Estonia's metal volumes per ton of mined material are rather modest. But as we're already surveying our mineral situation, it makes sense to take a closer look. In other words, we need to understand which parts of what's in the ground can be successfully processed.

The plan was to have a report for the government by the end of next year. Is this deadline still realistic, considering tenders have not gone according to schedule?

Our goal today is to finish the report on time. I believe that if we manage to find the technological testing partner in the next few months, we will be done by the end of 2025.

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