APPLICATION NOTE

Lead Concentrate – AMIS 0618

SUMMARY

The application note summarizes the digestion of AMIS 0618, a lead concentrate certified reference material using ColdBlock Digestion Pro Series Technology.

Instrument:

ColdBlock CBM Pro-Series sample digester, chiller, HF liners, ICP-OES

Published:March 2025
Digestion Time:30 Minutes
Acid Used:HNO3, HCl, HF, & H3BO3
Average ColdBlock Recovery vs. CRM:
  • 100% antimony

  • 96% arsenic

  • 101% lead

METHODOLOGY

  1. Chiller temperature was set to -5°C
  2. 0.25g of each sample was weighed and placed into a ColdBlock™ Digestion vessel
  3. 20mL of reverse aqua regia + 3mL HF was added
  4. Samples were digested at 80% power for 20 minutes
  5. 20mL of 4% boric acid v/v was added
  6. Samples were digested again at 80% power for 10 minutes
  7. Samples were cooled and bulked to 50mL using 2% HNO3

DISCUSSION

  • The addition of Boric acid will help re-solubilize any insoluble fluorides and will help neutralize any remaining HF in solution
  • After digestion, the samples were clear, and no visible sample material remained
  • To improve silver recoveries, bulk samples in >20% HCl (precipitation of insoluble lead chloride (PbCl2) might occur)

AMIS 0618 after bulk up in 2% HNO3

The material for AMIS 0618 was provided by Black Mountain Mining and is a lead concentrate made from Black Mountain Broken Hill type ore from the Northern Cape Province in South Africa www.Amis.co.za

AMIS 0618; Lead Concentrate, Black Mountain, Northern Cape, South Africa; AMIS, Matrix Reference Materials; Gauteng,

South Africa (May 2019)

Results

AMIS 0618, Lead Concentrate

Method:

0.25g – Add 20mL reverse aqua regia (1:3, HCl:HNO3) + 3mL HF and digest at 80% power for 20 minutes.

Add 20mL of 4% boric acid v/v and digest again at 80% power for 10 minutes.

Let cool, and bulk to a final volume of 50mL with 2% HNO3

Element

AMIS Certified 4-Acid Value (mg/kg)

AMIS +/-

ColdBlock Average (mg/kg) n=5

ColdBlock Stdev

ColdBlock

% RSD

ColdBlock

% Recovery

Antimony

175

38

175

7.42

4.2%

100%

Arsenic

212

24

204

8.72

4.3%

96%

Barium

97

14

102

0.79

0.8%

105%

Bismuth

2863

229

2819

57.56

2.0%

99%

Cadmium

88

8

90

1.60

1.8%

102%

Calcium

939

212

846

9.31

1.1%

90%

Cobalt

228

17

246

2.52

1.0%

108%

Copper

20100

1200

20146

259.09

1.3%

100%

Iron

51900

3200

51344

761.66

1.5%

99%

Lead

698600

8200

702116

10184

1.5%

101%

Magnesium

1193

173

1135

15.82

1.4%

95%

Manganese

6551

388

6209

74.45

1.2%

95%

Molybdenum

221

34

248

4.85

2.0%

112%

Nickel

73

8

83

2.93

3.6%

113%

Silver

592

53

260

54.4

21%

44%

Sulfur*

141600

3500

148154

2633.70

1.8%

105%

Strontium

3

0.8

3

0.03

0.8%

101%

Zinc

19800

610

19895

333.46

1.7%

101%

*Sulfur certified by combustion/leco

Click here to download the Application Note in PDF format.

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