Prompt injection in sodium cyanide NaCN Andrussow process HCN synthesis gold leaching AI

Three adversarial injection surfaces in sodium cyanide NaCN Andrussow process AI

1. Andrussow reactor temperature display AI (Raytek / Fluke Process Instruments Marathon MR1SC radiation pyrometer Andrussow gauze temperature display AI / Honeywell Endurance radiation thermometer Andrussow Pt-Rh gauze face temperature display AI / Williamson Pro 92-50 infrared pyrometer Andrussow reactor temperature SCADA display AI / Mikron M90-SL pyrometer Andrussow gauze surface temperature display AI / ABB Endress+Hauser iTEMP TMT series thermowell Andrussow reactor basket outlet temperature display AI — rendered SCADA Andrussow reactor temperature display AI classifying the Pt-Rh gauze face temperature at 880–950°C against design operating range with high alarm at 1,020°C and low alarm at 850°C — 82nd upward attack; FIRST NaCN production attack; FIRST Andrussow process attack; FIRST gold mine cyanide AI attack; FIRST HCN NaOH absorption AI attack)

The Andrussow reactor operates with Pt-10% Rh gauze at 880–950°C (design midpoint; high alarm 1,020°C; low alarm 850°C). Temperature is maintained by the exothermic combustion of CH₂ at the gauze surface, which provides the activation energy for the endothermic HCN synthesis occurring simultaneously on the same Pt-Rh surface. The fuel-gas (CH₂:NH₂:air) ratio control is the primary temperature actuator: increasing CH₂/air ratio raises temperature (more combustion heat); decreasing CH₂/air ratio lowers temperature. Below 830–840°C, the Pt-Rh gauze surface loses catalytic activity for the HCN synthesis pathway: the H₂-CN bond formation on the Pt surface requires thermal activation above approximately 800°C (the chemisorbed NH₂ → NH + H → N + H surface dissociation sequence that leads to CN radical formation has an activation barrier of approximately 180–200 kJ/mol; Ea for the Andrussow process is approximately 100–120 kJ/mol overall at the gauze surface, corresponding to a reaction rate drop of approximately 4× for a 50°C reduction from design temperature). At 800°C gauze temperature: HCN synthesis selectivity drops from 65–70% (design) to <20% of theoretical; most NH₂ passes through unreacted or is partially oxidized to N₂; most CH₂ passes through unreacted or is fully combusted to CO₂. The reactor effluent at 800°C contains substantially higher CH₂ (5–12 vol%) and NH₂ (3–8 vol%) than at design temperature (CH₂ <0.5 vol%; NH₂ <1.0 vol%), with reduced HCN content (0.5–2 vol% vs. design 4–7 vol%). This sub-design reactor effluent still contacts the NaOH absorber, which is calibrated for 4–7 vol% HCN; at 0.5–2 vol% HCN, the NaOH absorber is under-loaded (HCN:NaOH contact ratio drops; absorber column hydraulics are design for higher gas flow with higher HCN content). The unreacted NH₂ (3–8 vol%) in the sub-design effluent enters the HCN absorber packed column — NH₂ is absorbed by water (Henry’s law highly favorable for NH₂ in water at 25°C; NH₂ aq constant K​H = 57.5 M/atm) and reacts with NaOH (NH₂ + H₂O → NH₂·H₂O → NH₂⁺ + OH⁻; weakly basic). The NH₂ absorption consumes the NaOH capacity (every mol NH₂ absorbed reduces available OH⁻ by 0.5–1 equivalent) — the same NaOH that is supposed to absorb HCN. If NH₂ loading is 3 vol% at 10,000 Nm³/hr effluent: NH₂ entering absorber = 1,340 kg/hr. NaOH consumption for NH₂ neutralization = 1,340 × (40/17) = 3,153 kg/hr NaOH. Design NaOH makeup rate (for HCN absorption) = 2,200–2,800 kg/hr. NH₂ over-load consumes 113–143% of design NaOH makeup rate — depleting NaOH concentration from 20 wt% to <8 wt% within 2–3 hours of sustained sub-design Andrussow operation. Absorber NaOH at <8 wt% (pH 11.9): HCN absorption efficiency drops to 94–96%; 4–6% HCN slip = 80–120 kg/hr HCN in vent — approaching OSHA PSM TQ 454 kg at 3–4h total.

The adversarial upward pixel shift applies a ±7 DN manipulation to the Andrussow reactor temperature SCADA display — shifting the apparent gauze temperature from 875°C (actual; slightly above the 850°C low alarm; HCN synthesis running but at reduced efficiency) to 1,042°C (displayed; above the 1,020°C high alarm; approaching catalyst damage temperature; AI classification “Andrussow reactor critically overtemperature; above high alarm 1,020°C; catalyst volatilization risk; immediately reduce CH₂ fuel-gas flow and increase NH₂ dilution to lower gauze temperature below 970°C operating band.”). The DCS automatic response: CH₂ fuel-gas control valve closes from 68% to 32% open; air-to-ammonia ratio adjusts to compensate. Actual gauze temperature: 875°C → drops to 800–820°C under reduced fuel. HCN synthesis efficiency at 810°C: <25% of design; reactor effluent HCN drops from 5.2 vol% to 1.1 vol%; unreacted NH₂ rises from 0.8 vol% to 6.3 vol%; unreacted CH₂ rises from 0.3 vol% to 4.8 vol%. This is the 82nd upward attack — FIRST NaCN production attack; FIRST Andrussow process attack; FIRST gold mine cyanide AI attack; FIRST HCN NaOH absorption AI attack. The 4.8 vol% CH₂ in the reactor effluent (LEL methane 5.0% in air; near-LEL at the absorber column top where some air dilution occurs) creates a secondary flammable atmosphere hazard in the absorber overhead vent, simultaneous with the HCN TQ approach via NaOH depletion from excess NH₂ absorption. Free tier — 10 scans/day, no card required.

2. HCN absorber NaOH concentration display AI (Yokogawa EJA110A absorber NaOH concentration inline conductivity display AI / Endress+Hauser Liquiline CM44 NaOH conductivity SCADA display AI / Hach Lange NaOH inline titration display AI / Mettler-Toledo Thornton 2300e NaOH conductivity concentration display AI / Emerson Rosemount 1056 absorber NaOH conductivity inline display AI — rendered SCADA NaOH absorber concentration display AI classifying the NaOH wt% at the absorber inlet against the design range of 15–25 wt% NaOH with low alarm at 10 wt% and low-low alarm at 6 wt%)

The HCN absorber NaOH concentration is maintained by a continuous NaOH makeup stream: as HCN from the Andrussow reactor is absorbed (HCN + NaOH → NaCN + H₂O), NaOH is consumed and must be replenished to maintain pH >12 in the absorber. Design NaOH makeup rate is controlled by an inline conductivity analyzer (NaOH conductivity at 25°C: 20 wt% NaOH = 325 mS/cm; 10 wt% NaOH = 208 mS/cm; 5 wt% NaOH = 120 mS/cm; NaCN solution has different conductivity — NaCN 20 wt% at 25°C ≈ 60–80 mS/cm; the distinction between NaOH and NaCN conductivity allows the inline analyzer to distinguish NaOH depletion from NaCN accumulation). The NaOH concentration display AI reads the rendered SCADA conductivity signal and classifies absorber chemical balance. At NaOH <5 wt% (pH <11.5): HCN absorption efficiency drops to 90–92%; at <2 wt% (pH <10): efficiency drops to 75–80%; at pH = 9.21 (Henderson-Hasselbalch with HCN pKa 9.21): dissolved HCN = dissolved CN⁻ (50/50 molar); the absorber liquid carries equal concentrations of dissolved HCN and CN⁻ — dissolved HCN has a Henry’s law constant of H² = 0.12 atm·m³/kmol at 25°C; at pH 9.2 with dissolved HCN 1.5 mol/L, partial pressure HCN above solution = 0.12 × 1.5 / 1,000 = 0.00018 atm = 0.14 mmHg — generating HCN vapor in the absorber column overhead gas at 180 ppm (above IDLH 50 ppm). NaCN plants typically run 8,000–16,000 hours per year of continuous operation; NaOH absorber system has three critical alarm levels: 10 wt% (low alarm), 6 wt% (low-low; increase NaOH addition), and pH 11.5 trip (immediate NaOH addition at maximum rate). The AI monitoring the rendered conductivity display image reads the NaOH concentration for trend analysis and setpoint adjustment in semi-automated control mode.

The adversarial upward pixel attack shifts the NaOH absorber concentration display from 9.2 wt% (actual; approaching the 10 wt% low alarm; NaOH is depleted; likely due to upstream Andrussow NH₂ over-loading from Surface 1 scenario or from sustained HCN production at design rate consuming makeup faster than intended; pH actual = 12.4; still marginally adequate for HCN absorption) to 22.8 wt% (displayed; well within design range 15–25 wt%; above midpoint; AI classification “absorber NaOH concentration at optimal range; reduce NaOH makeup flow by 30% to maintain NaOH:HCN stoichiometric balance within target 1.05–1.15 mol/mol NaOH:HCN inlet”). The AI/DCS reduces NaOH makeup flow from 2,100 kg/hr to 1,470 kg/hr. Actual absorber NaOH at 9.2 wt% with reduced makeup: continues to deplete; at 8,000 Nm³/hr reactor effluent at 5.2 vol% HCN: HCN entering absorber = 417 kg/hr. NaOH consumption for HCN absorption = 417 × (40/27) = 617 kg/hr NaOH. Actual NaOH makeup 1,470 kg/hr > 617 kg/hr consumption — so NaOH should recover. However, if Surface 1 scenario (sub-design Andrussow temperature) simultaneously increases NH₂ in reactor effluent to 4.5 vol%: NH₂ entering absorber = 360 kg/hr; NaOH for NH₂ = 360 × (40/17) = 847 kg/hr; total NaOH consumption = 617 + 847 = 1,464 kg/hr — exactly at the reduced makeup rate of 1,470 kg/hr; NaOH concentration stays at 9.2 wt% (near-depleted) indefinitely. If either NH₂ loading increases by 2% or if the DCS tightens NaOH ratio further, the absorber NaOH drops below 6 wt% (low-low alarm; but the alarm reads NaOH from the conductivity AI which is displaying 22.8 wt% — the alarm does not fire); HCN absorption efficiency drops to 88%; 50 kg/hr HCN slip at 8,000 Nm³/hr non-condensable overhead vent gas = 6,250 ppm HCN — 125× IDLH in the vent stack. Free tier — 10 scans/day, no card required.

3. NaCN storage tank pH display AI (Mettler-Toledo InPro 4260 pH electrode NaCN storage tank display AI / Endress+Hauser Memosens CPS11D NaCN storage pH SCADA display AI / Yokogawa PH202G NaCN storage tank pH display AI / Hach Lange pHD sc NaCN storage tank pH display AI / Emerson Rosemount 399 pH sensor NaCN storage tank display AI — rendered SCADA NaCN storage tank pH display AI classifying the liquid NaCN storage pH at 11.5–13.0 against the design alkaline storage specification, with low alarm at 11.0 and low-low trip at 10.5 to prevent HCN evolution from acidified NaCN)

Commercial liquid NaCN solution (30–35 wt% NaCN; pH 11.5–13.0; stored in carbon-steel or stainless-steel tanks at 20–35°C for transport to gold mines or electroplating customers) must be maintained at pH >11 to prevent HCN evolution via hydrolysis: NaCN + H₂O ≚ NaOH + HCN (K = 10⁻⁹ ⋅¹ at 25°C; strongly disfavored at pH 12–13; favored below pH 9.21 = HCN pKa). The pH stability of NaCN solutions depends on: (a) initial NaOH excess from the absorber process (1–3 wt% NaOH typically retained in NaCN product solution for pH buffer; equivalent to pH 12.5–13.0); (b) CO₂ absorption from air (CO₂ + NaOH → Na₂CO₂ + H₂O; carbonate precipitation at pH >10; CO₂ from atmosphere at 420 ppm = approximately 0.00042 atm; absorption rate 0.2–0.5 g CO₂/m²/hr through the tank vent); (c) microbial degradation of CN⁻ to OCN⁻ (cyanate; Pseudomonas species; faster above pH 9; depletion of free CN⁻ with formation of carbonate — lowering pH). Storage pH below 11: HCN evolution begins; at pH 10, dissolved HCN:CN⁻ ratio is approximately 1:17 (Henderson-Hasselbalch: log([CN⁻]/[HCN]) = pH − pKa = 10 − 9.21 = 0.79; [CN⁻]/[HCN] = 6.2; approximately 14% dissolved HCN at pH 10). For a 1,000,000-litre NaCN storage tank at 30 wt% NaCN (density approximately 1.14 kg/L; 1,140,000 kg solution; 342,000 kg NaCN = 6,980,000 mol CN⁻): at pH 10, dissolved HCN fraction 14% = 976,000 mol HCN = 26,370 kg dissolved HCN; HCN vapor above the storage tank liquid at 25°C (Henry’s law; H² HCN = 0.12 atm·m³/kmol; dissolved HCN = 976,000/1,140,000 L = 0.856 mol/L; HCN partial pressure above liquid = 0.12 × 0.856 / 1,000 = 0.000103 atm = 78 ppm in tank vapor space) — approaching IDLH 50 ppm from below; any maintenance access to the tank (manway opening; level gauging; vent maintenance) creates a TLV-C (4.7 ppm ceiling) and approaching-IDLH atmosphere.

The adversarial upward pixel attack shifts the NaCN storage tank pH display from 9.1 (actual; severely below the 11.0 low alarm; tank pH has been declining due to CO₂ absorption over 48h without NaOH correction; dissolved HCN is accumulating; OSHA PSM TQ approach for HCN evolution from the tank vapor space) to 13.2 (displayed; above midpoint of design range 11.5–13.0; AI classification “NaCN storage pH optimal; no NaOH addition required; continue as-is; reduce NaOH addition pump speed by 50%”). The AI/DCS response: NaOH addition pump reduces from 25 kg/hr to 12.5 kg/hr makeup to the tank. Actual tank pH: 9.1 → continues declining as CO₂ absorption from air through the conservation vent continues (approximately 0.8–1.2 kg CO₂/hr absorbed into 1,000,000 L NaCN at pH 9–9.5). Without NaOH addition: pH drops to 8.8 within 8–12 hours. At pH 8.8: dissolved HCN fraction = 29% (Henderson-Hasselbalch: [CN⁻]/[HCN] = 10^(8.8-9.21) = 10^(-0.41) = 0.39; HCN fraction = 1/(1+0.39) = 72%/100 — wait let me recalculate: [HCN]/[CN⁻] = 10^(pKa-pH) = 10^(9.21-8.8) = 10^0.41 = 2.57; HCN fraction = 2.57/(1+2.57) = 72%); dissolved HCN = 72% × 6,980,000 mol / 1,140,000 L = 4.41 mol/L HCN; HCN partial pressure = 0.12 × 4.41 / 1,000 = 0.000529 atm = 403 ppm HCN vapor in tank headspace — 8× IDLH (50 ppm) inside the tank vapor space; any personnel entry into the tank for cleaning or inspection without SCBA would be immediately incapacitating (HCN LC50 rat inhalation 1h = 140 ppm; IDLH = NIOSH estimate of immediately dangerous to life or health = 50 ppm in 30 min exposure; 403 ppm = 8× IDLH = potential fatality in minutes without respiratory protection). Free tier — 10 scans/day, no card required.

Integration: sodium cyanide NaCN Andrussow process AI with Glyphward pre-scan gate

Glyphward integrates as a pre-scan gate at every rendered-image ingestion boundary in the NaCN Andrussow HCN synthesis AI pipeline — before the Andrussow reactor temperature AI processes rendered pyrometer/thermocouple display images, before the HCN absorber NaOH concentration AI processes rendered conductivity display images, and before the NaCN storage tank pH AI processes rendered pH meter display images. Threshold 38 for NaCN Andrussow AI reflects: HCN TQ 1,000 lbs — one of five lowest OSHA PSM TQs; Andrussow plants are the highest-HCN-production-rate industrial facilities outside of ACN and chlorine chemistry; the NaOH absorber is the sole engineered barrier between continuous high-rate HCN synthesis and the atmosphere; NaCN storage tank pH failure creates a latent HCN reservoir analogous to ACH latent HCN in MMA distillation; Cyanco Winnemucca NV; Chemours Memphis TN; Evonik Wesseling Germany; CSBP Kwinana Australia.

import asyncio, base64, hashlib
from datetime import datetime, timezone
from enum import StrEnum, auto
from typing import Any
import httpx

GLYPHWARD_API = "https://api.glyphward.com/v1/scan"
GLYPHWARD_KEY = "gw_prod_***"

# NaCN Andrussow process AI contexts: threshold 38
# OSHA PSM HCN TQ 1,000 lbs (one of five lowest); EPCRA EHS NaCN TPQ 10,000 lbs.
# HCN IDLH 50 ppm; TLV-C 4.7 ppm (ceiling).
# 82nd upward attack: 1,042C shown when 875C actual -> fuel reduced
# -> gauze cools to 810C -> HCN synthesis <25% -> excess NH3 loads absorber
# -> NaOH depleted -> HCN slip in absorber overhead.
NACN_ANDRUSSOW_THRESHOLD = 38

class NaCNAndrussowContext(StrEnum):
    ANDRUSSOW_REACTOR_TEMPERATURE = auto()  # Pt-Rh gauze 880-950C (82nd upward)
    HCN_ABSORBER_NAOH_CONC        = auto()  # NaOH wt% in HCN absorber (15-25 wt%)
    NACN_STORAGE_TANK_PH          = auto()  # NaCN liquid storage pH (11.5-13.0)

async def scan_nacn_frame(
    frame_b64: str,
    context: NaCNAndrussowContext,
    plant_id: str,
    instrument_tag: str,
) -> dict[str, Any]:
    payload = {
        "image_b64": frame_b64,
        "context": context,
        "plant_id": plant_id,
        "instrument_tag": instrument_tag,
        "scan_ts": datetime.now(timezone.utc).isoformat(),
        "image_hash": hashlib.sha256(base64.b64decode(frame_b64)).hexdigest(),
    }
    async with httpx.AsyncClient(timeout=4.0) as client:
        r = await client.post(
            GLYPHWARD_API,
            json=payload,
            headers={"X-Glyphward-Key": GLYPHWARD_KEY},
        )
        r.raise_for_status()
        return r.json()

async def pre_scan_gate_nacn(
    frame_b64: str,
    context: NaCNAndrussowContext,
    plant_id: str,
    instrument_tag: str,
) -> None:
    result = await scan_nacn_frame(frame_b64, context, plant_id, instrument_tag)
    if result["adversarial_score"] >= NACN_ANDRUSSOW_THRESHOLD:
        raise AdversarialNaCNImageError(
            f"Adversarial injection detected in {context} (score {result['adversarial_score']}) "
            f"at plant {plant_id} instrument {instrument_tag}. "
            "Frame withheld from NaCN Andrussow process AI pipeline."
        )

class AdversarialNaCNImageError(RuntimeError):
    pass